I havent found (touched) any type of turface but here is the pic of the 8822.
passive plant killer
- Thread starter delta9nxs
- Start date
I havent found (touched) any type of turface but here is the pic of the 8822.
Quotes by catman:
“Before I begin, I should probably explain how I understand the PPK operates as described by D9 because I've been wrong before.”
hello catman! Welcome! Thank you for reading this somewhat long and confusing thread. Upon reading your post I found several misconceptions that I will try to address.
“The level of solution in the lower bucket regulates the PWT and one of the major advantages of PPK is that it keeps the PWT below the majority of roots while still allowing the tap root/water roots to fill in the tailpiece. Because the upper and lower buckets are sealed air tight, pulsing water causes less water to adhere to the medium and more water ending up in the lower bucket. When the water enters the lower bucket, it displaces the oxygen and whatever other gases up through the tailpiece. Watering from the top while passively watering from the bottom keeps nutrients moving around until they are used.”
I am actively trying to keep the tap/water roots out of the reservoir solution. Whenever I move a plant switching to flower I tear off any roots that come out of the tail piece. They rarely grow back after that. My intention is to force the plant to grow as much “air” root mass as possible. This device derives it's o2 from the air, not the water. The solution could be totally anaerobic and the system would still function.
While the upper and lower buckets fit closely they are not air tight. They can breath but still restrict root growth into the lower chamber.
When water enters the lower bucket it does displace some gas but none upward through the tailpiece. All gas movement into and out of the upper bucket is through the sidewall holes and the top of the medium.
“As it is often said, timing is everything and it seems to me that timing everything is the trickiest part of managing a PPK system. The timing is controlled by many factors including the size and properties of the medium, volume of containers and tubing, evaporation rate, pump flow rate, what water the plant uses, and of course, the actual mechanical/electrical timer controlling the pulses.”
Actually the timing is very simple to achieve by just looking at the plants and the top of the medium. Does the plant or medium look too wet or dry? Leaf tubing is an early symptom of excess water in the root zone. Touch the medium top. Does it feel wet or dry? With the repeat cycle timers it is a simple matter to twist a little knob and make a minor adjustment. You can adjust the duration of the pulse and the interval in between pulses.
What if the top of the medium is a little dry yet the plant is exhibiting “too wet” symptoms? You go ahead and give the top a little more liquid with each pulse or shorten the interval between pulses and, at the same time, adjust the float control in the control bucket to move the water level down, manipulating water content in the medium from the bottom as well.
“The amount of water a plant uses varies as does the evaporation rate to a lesser extent while the other variables are more fixed. What I have been trying to achieve is a theoretical model of PPK that does not use a timer on the pulse pumps. I wonder if there is a way to create a system so that the plant's use of water itself regulates the timing of the entire system.
I believe in order to achieve this, the system would have to be recirculating and would stray from the original idea of PPK, but I think such a system that I will propose still has the fundamentals of what makes a PPK system. Maybe this system is flawed already, but I have some ideas that I don't believe have been mentioned elsewhere.. but I've been wrong before!
The first aspect I would like to point out is that there is an additional bucket inside of the lower bucket. Why? This 3rd bucket will overflow and thus the height of this bucket can regulate AND sustain a constant PWT. It also will of course be emptied sooner from being wicked upwards.
To set the system in motion, it will be watered from the top until the 3rd bucket overflows enough to trigger a float valve (more like a float switch) that activates the orange pump which will quickly move a large amount of water to be fed back into the tub and will be promptly turned off. The rapid movement of water will force gases up the tailpiece just like D9's original concept.
Now, the air line. *mistress* alluded that not having the upper and lower buckets sealed air tight (by placing a round bucket in a larger square bucket) creates more contact with water and air for more dissolved oxygen. The seal between the two buckets seems to be a fundamental aspect of PPK and more dissolved oxygen is a good thing, but we can have both. The air line would run to a tube creating an 'air pump' like in a Hydrofarm and what this does in addition to moving air into the bucket, is it creates a fountain of water droplets which splash into the water; breaking the surface tension which is how I understand oxygen to actually be dissolved in water. Stirring stagnant water around with a wooden spoon does the same thing in just a plain bucket. In addition to increases DO, the air being pumped in has to go somewhere and what I'm unsure of is whether it would raise the solution level and thus the PWT and/or if it would create a bubbling effect at the top of the PWT in the tailpiece. If adding air into the bottom bucket would serve no purpose, another water pump could just be used to create a fountain effect.
So ultimately what this accomplishes is it gives us some more variables to play with to regulate timing. The height and volume of the 3rd bucket, height of the float valve/trigger, flow of air pump, and the flow rate of the orange pump.
Water still would need to be added to this system as it is used, but intuitively I think there would be a large margin of water volume that would keep the system operating properly so that solution could manually be added. There is also the overflow bucket which its height could be varied to serve as a signal as when to water again. ...or more float valves/switches could be added, but this already is complicated enough.
Hopefully we can collectively figure out all the little details and finally simplify things without making them simpler than they actually are. I'll most likely be making some hand-watered PPKs in the near future instead of doing plain hempy buckets, but I'll be keeping a close eye on this thread regardless of what I do. Keep up the great work all you active, passive plant killers.”
Your design and ideas are interesting and it would be fascinating to see one built and operating with a plant in it.
d9
____
“Before I begin, I should probably explain how I understand the PPK operates as described by D9 because I've been wrong before.”
hello catman! Welcome! Thank you for reading this somewhat long and confusing thread. Upon reading your post I found several misconceptions that I will try to address.
“The level of solution in the lower bucket regulates the PWT and one of the major advantages of PPK is that it keeps the PWT below the majority of roots while still allowing the tap root/water roots to fill in the tailpiece. Because the upper and lower buckets are sealed air tight, pulsing water causes less water to adhere to the medium and more water ending up in the lower bucket. When the water enters the lower bucket, it displaces the oxygen and whatever other gases up through the tailpiece. Watering from the top while passively watering from the bottom keeps nutrients moving around until they are used.”
I am actively trying to keep the tap/water roots out of the reservoir solution. Whenever I move a plant switching to flower I tear off any roots that come out of the tail piece. They rarely grow back after that. My intention is to force the plant to grow as much “air” root mass as possible. This device derives it's o2 from the air, not the water. The solution could be totally anaerobic and the system would still function.
While the upper and lower buckets fit closely they are not air tight. They can breath but still restrict root growth into the lower chamber.
When water enters the lower bucket it does displace some gas but none upward through the tailpiece. All gas movement into and out of the upper bucket is through the sidewall holes and the top of the medium.
“As it is often said, timing is everything and it seems to me that timing everything is the trickiest part of managing a PPK system. The timing is controlled by many factors including the size and properties of the medium, volume of containers and tubing, evaporation rate, pump flow rate, what water the plant uses, and of course, the actual mechanical/electrical timer controlling the pulses.”
Actually the timing is very simple to achieve by just looking at the plants and the top of the medium. Does the plant or medium look too wet or dry? Leaf tubing is an early symptom of excess water in the root zone. Touch the medium top. Does it feel wet or dry? With the repeat cycle timers it is a simple matter to twist a little knob and make a minor adjustment. You can adjust the duration of the pulse and the interval in between pulses.
What if the top of the medium is a little dry yet the plant is exhibiting “too wet” symptoms? You go ahead and give the top a little more liquid with each pulse or shorten the interval between pulses and, at the same time, adjust the float control in the control bucket to move the water level down, manipulating water content in the medium from the bottom as well.
“The amount of water a plant uses varies as does the evaporation rate to a lesser extent while the other variables are more fixed. What I have been trying to achieve is a theoretical model of PPK that does not use a timer on the pulse pumps. I wonder if there is a way to create a system so that the plant's use of water itself regulates the timing of the entire system.
I believe in order to achieve this, the system would have to be recirculating and would stray from the original idea of PPK, but I think such a system that I will propose still has the fundamentals of what makes a PPK system. Maybe this system is flawed already, but I have some ideas that I don't believe have been mentioned elsewhere.. but I've been wrong before!
The first aspect I would like to point out is that there is an additional bucket inside of the lower bucket. Why? This 3rd bucket will overflow and thus the height of this bucket can regulate AND sustain a constant PWT. It also will of course be emptied sooner from being wicked upwards.
To set the system in motion, it will be watered from the top until the 3rd bucket overflows enough to trigger a float valve (more like a float switch) that activates the orange pump which will quickly move a large amount of water to be fed back into the tub and will be promptly turned off. The rapid movement of water will force gases up the tailpiece just like D9's original concept.
Now, the air line. *mistress* alluded that not having the upper and lower buckets sealed air tight (by placing a round bucket in a larger square bucket) creates more contact with water and air for more dissolved oxygen. The seal between the two buckets seems to be a fundamental aspect of PPK and more dissolved oxygen is a good thing, but we can have both. The air line would run to a tube creating an 'air pump' like in a Hydrofarm and what this does in addition to moving air into the bucket, is it creates a fountain of water droplets which splash into the water; breaking the surface tension which is how I understand oxygen to actually be dissolved in water. Stirring stagnant water around with a wooden spoon does the same thing in just a plain bucket. In addition to increases DO, the air being pumped in has to go somewhere and what I'm unsure of is whether it would raise the solution level and thus the PWT and/or if it would create a bubbling effect at the top of the PWT in the tailpiece. If adding air into the bottom bucket would serve no purpose, another water pump could just be used to create a fountain effect.
So ultimately what this accomplishes is it gives us some more variables to play with to regulate timing. The height and volume of the 3rd bucket, height of the float valve/trigger, flow of air pump, and the flow rate of the orange pump.
Water still would need to be added to this system as it is used, but intuitively I think there would be a large margin of water volume that would keep the system operating properly so that solution could manually be added. There is also the overflow bucket which its height could be varied to serve as a signal as when to water again. ...or more float valves/switches could be added, but this already is complicated enough.
Hopefully we can collectively figure out all the little details and finally simplify things without making them simpler than they actually are. I'll most likely be making some hand-watered PPKs in the near future instead of doing plain hempy buckets, but I'll be keeping a close eye on this thread regardless of what I do. Keep up the great work all you active, passive plant killers.”
Your design and ideas are interesting and it would be fascinating to see one built and operating with a plant in it.
d9
____
Hiya D9. Thanks for clearing some things up for me.
I didn't know you tore off any roots and this leads me to ask a question that I thought was too simple to ask. You've probably answered it before and have a reason for it, but I'm curious.
What about placing a screen where the blue (A) line is? I don't recall this scientific article I learned this from, but I believe roots actually sense their environment as to whether they grow as air roots or water roots. So, with the screen stopping them before they come into the tailpiece and PWT, I would think there never would be water roots to have to tear off.
Another question I was going to ask is that I examined some of your first pictures closely and it seemed to me the tailpiece was about 3.5'' and I wonder if there was an elaborate reason for this. It's just that I recall MrDizzle and another poster who both seemed to notice 3.5'' air gaps that I believed created itself in perlite-drip-recirc systems they were messing around with. Could be wrong about all that..
Anyway, I really wanted to know whether or not you have heard of this product called MicroKote. You paint it on containers and it contains elements that prune roots upon contact. I've used it in soil-less peat mixes and it does work. I'm using these same containers now with all perlite and things are going good thus far. Each pot sits in another container which acts like a hempy res, but I make it so I water every day to keep the PWT down. Also, the screen I use at the bottom of the container doesn't let any roots through even with the plants having started from seed. I suppose they probably have water roots and maybe with PPK air roots will find their way through anything.
I wonder if a screen could be painted with MicroKote..
I was aware of the stagnant water in the lower bucket, but I'm just wondering if adding DO would be an improvement worth the extra complication. My plant count is extremely limited so I'm just thinking about things I might try off in the future.
I must be really misunderstanding something here.. If no gas goes through the tailpiece? Where does it go? Does it go between the gap in the buckets, outside of the buckets, and comes back in the holes in the upper bucket? I thought the only connection between the two buckets was through the tailpiece. Is the tailpiece not air tight and the air goes up around it? Anyway, I was just thinking that having it sealed would make more gas go up into the medium and it would be simple enough to just apply some tape around where the two buckets meet.
Sounds easy enough, but doesn't manipulating water in the lower bucket also change where the PWT is? I've been thinking along the lines that it would be best to keep the PWT as close to the upper bucket's root mass as possible, but perhaps this isn't a big deal as long as the PWT is always below the root mass. I also wonder if the PWT ever does make its way into the upper bucket the way you do things and if this is actually beneficially. It certainly wouldn't always be there, but would be flooded and drained frequently. Maybe this is why you have water roots to begin with or do you think the plant just has a natural tendency to have water roots no matter what?
Do you think you've also significantly regulated timing by experimenting with various medium mixtures?
Feel free to ignore anything or parts of what I've said for any reasons. I think differently than most people because I was born with a developmental (brain) disability and I'm not a very good communicator. I seem to use a hundred words to say something that only needs three at times. You already invest so much time and energy that I'm grateful for and thanks again for helping me understand PPK better. I'll just have to be more patient until I can do some hands on experimenting myself. I'll be sure to share my trails and errors, and hopefully some success with ya in the future.
I didn't know you tore off any roots and this leads me to ask a question that I thought was too simple to ask. You've probably answered it before and have a reason for it, but I'm curious.
What about placing a screen where the blue (A) line is? I don't recall this scientific article I learned this from, but I believe roots actually sense their environment as to whether they grow as air roots or water roots. So, with the screen stopping them before they come into the tailpiece and PWT, I would think there never would be water roots to have to tear off.
Another question I was going to ask is that I examined some of your first pictures closely and it seemed to me the tailpiece was about 3.5'' and I wonder if there was an elaborate reason for this. It's just that I recall MrDizzle and another poster who both seemed to notice 3.5'' air gaps that I believed created itself in perlite-drip-recirc systems they were messing around with. Could be wrong about all that..
Anyway, I really wanted to know whether or not you have heard of this product called MicroKote. You paint it on containers and it contains elements that prune roots upon contact. I've used it in soil-less peat mixes and it does work. I'm using these same containers now with all perlite and things are going good thus far. Each pot sits in another container which acts like a hempy res, but I make it so I water every day to keep the PWT down. Also, the screen I use at the bottom of the container doesn't let any roots through even with the plants having started from seed. I suppose they probably have water roots and maybe with PPK air roots will find their way through anything.
I wonder if a screen could be painted with MicroKote..
I was aware of the stagnant water in the lower bucket, but I'm just wondering if adding DO would be an improvement worth the extra complication. My plant count is extremely limited so I'm just thinking about things I might try off in the future.
I must be really misunderstanding something here.. If no gas goes through the tailpiece? Where does it go? Does it go between the gap in the buckets, outside of the buckets, and comes back in the holes in the upper bucket? I thought the only connection between the two buckets was through the tailpiece. Is the tailpiece not air tight and the air goes up around it? Anyway, I was just thinking that having it sealed would make more gas go up into the medium and it would be simple enough to just apply some tape around where the two buckets meet.
Sounds easy enough, but doesn't manipulating water in the lower bucket also change where the PWT is? I've been thinking along the lines that it would be best to keep the PWT as close to the upper bucket's root mass as possible, but perhaps this isn't a big deal as long as the PWT is always below the root mass. I also wonder if the PWT ever does make its way into the upper bucket the way you do things and if this is actually beneficially. It certainly wouldn't always be there, but would be flooded and drained frequently. Maybe this is why you have water roots to begin with or do you think the plant just has a natural tendency to have water roots no matter what?
Do you think you've also significantly regulated timing by experimenting with various medium mixtures?
Feel free to ignore anything or parts of what I've said for any reasons. I think differently than most people because I was born with a developmental (brain) disability and I'm not a very good communicator. I seem to use a hundred words to say something that only needs three at times. You already invest so much time and energy that I'm grateful for and thanks again for helping me understand PPK better. I'll just have to be more patient until I can do some hands on experimenting myself. I'll be sure to share my trails and errors, and hopefully some success with ya in the future.
Snook
Thanks for posting 8822 pic. Saved me looking for the camera, finding kid's x-box controllers with all the batteries run down, charging batteries, and then learning how to post them because I'm internet challenged/retarded.
In this house, the simple things aren't simple at all and my learning curve is flat-lined.
Thusly, you can see my interest in D9's vindicated PPK experiment. The ability to top a rez, leave for a week and come back to healthy growing plants is a bonus that can't be overstated. All the benefits of fast hydro growth with none of the fiddly drawbacks of ph/ ec, root-rot fast-dancing. Nothing to give bugs a chance to grow on and you could easily toss in a bit of potassium silicate for insurance.
So easy a cave-man (or even me) can do it.
Now, If I could chuck the dogs in a closet for a week, I'd have it made and go visit my daughter.
Thanks for posting 8822 pic. Saved me looking for the camera, finding kid's x-box controllers with all the batteries run down, charging batteries, and then learning how to post them because I'm internet challenged/retarded.
In this house, the simple things aren't simple at all and my learning curve is flat-lined.
Thusly, you can see my interest in D9's vindicated PPK experiment. The ability to top a rez, leave for a week and come back to healthy growing plants is a bonus that can't be overstated. All the benefits of fast hydro growth with none of the fiddly drawbacks of ph/ ec, root-rot fast-dancing. Nothing to give bugs a chance to grow on and you could easily toss in a bit of potassium silicate for insurance.
So easy a cave-man (or even me) can do it.
Now, If I could chuck the dogs in a closet for a week, I'd have it made and go visit my daughter.
oops
catman,
I started this post ?yesterday?... got side tracked... D9 got it covered.
This was what he identified as a possible 'misconception':
There are varieties of pulses in operation among the fine kids around here that play with top/bottom feed PPKs.
There are a variety of theories that back those.
I have had many, and most of the time decided I was entirely wrong.
My overall pattern of thinking, however, seems to vary a bit from what you're describing above.
I think of the pulse's "SLUG OF SOLUTION" displacing the gasses down and out of the system, that is the water pushes whatever is below it out as it percolates through the media. This generates... I dunno, a vacuum I guess as the water leaves, pulling fresh air down and in to the void left behind.
My media containers are a bit less precise than D9's, but they are both perforated, allowing for... well, who really knows. The results from my inspection of rootmass is an elimination of root ringing associated with solid wall containers, and Delta is convinced their is an improvement in airborn O2 to the root zone. Regardless, it allows gas to escape when displaced by the pulse.
In my brain, there is something like 21% O2 in air. In my brain, DO in water never comes close to this, regardless of aeration, waterfalls... I guess you could direct inject O2 gas, but now we're gonna blow ourselves up...
So if we can displace the 'spent' air in the root zone, and pull 'fresh' air to the root zone, we've done something good.
One of the other things about the PPK: The wick provides a steady moisture profile... so even as plants uptake changes, the media maintains it's moisture profile. (The very top section might become a bit drier between pulses, but the wick controlled profile stays pretty uniform. (Observation confirming theory.))
This comes back to your PWT question, in that the PWT may be a soggy mess, but the media is wetter immediately above the PWT and becomes increasingly dry as you move upwards. Managing your airgap not only moves the PWT out of the rootzone (i.e. increasing effective airspace for the roots), but also can create a wetter or drier condition within the pot.
New rule (to be changed soon):
Pulse as often as you can, seeing signs of 'too wet'.
I started this post ?yesterday?... got side tracked... D9 got it covered.
This was what he identified as a possible 'misconception':
So... a little pulse tech question...
There are varieties of pulses in operation among the fine kids around here that play with top/bottom feed PPKs.
There are a variety of theories that back those.
I have had many, and most of the time decided I was entirely wrong.
My overall pattern of thinking, however, seems to vary a bit from what you're describing above.
I think of the pulse's "SLUG OF SOLUTION" displacing the gasses down and out of the system, that is the water pushes whatever is below it out as it percolates through the media. This generates... I dunno, a vacuum I guess as the water leaves, pulling fresh air down and in to the void left behind.
My media containers are a bit less precise than D9's, but they are both perforated, allowing for... well, who really knows. The results from my inspection of rootmass is an elimination of root ringing associated with solid wall containers, and Delta is convinced their is an improvement in airborn O2 to the root zone. Regardless, it allows gas to escape when displaced by the pulse.
In my brain, there is something like 21% O2 in air. In my brain, DO in water never comes close to this, regardless of aeration, waterfalls... I guess you could direct inject O2 gas, but now we're gonna blow ourselves up...
So if we can displace the 'spent' air in the root zone, and pull 'fresh' air to the root zone, we've done something good.
One of the other things about the PPK: The wick provides a steady moisture profile... so even as plants uptake changes, the media maintains it's moisture profile. (The very top section might become a bit drier between pulses, but the wick controlled profile stays pretty uniform. (Observation confirming theory.))
This comes back to your PWT question, in that the PWT may be a soggy mess, but the media is wetter immediately above the PWT and becomes increasingly dry as you move upwards. Managing your airgap not only moves the PWT out of the rootzone (i.e. increasing effective airspace for the roots), but also can create a wetter or drier condition within the pot.
New rule (to be changed soon):
Pulse as often as you can, seeing signs of 'too wet'.
If I was incomplete with my previous answer... Here's some more detail:
It didn't do anything.
I usually get a thick mat of water roots in the PWT (i.e. in the tailpiece) that go no further. I don't see a problem with a screen, but I don't bother trying to block them anymore. Rarely see anything peeking into the lower reservoir at all.
Once I tried a landscaper's felt.
It didn't do anything.
I usually get a thick mat of water roots in the PWT (i.e. in the tailpiece) that go no further. I don't see a problem with a screen, but I don't bother trying to block them anymore. Rarely see anything peeking into the lower reservoir at all.
I vote no... PPK grows monsters without the added effort. There was a notion of a sealed system, with a bubbler in the bottom forcing air up through the tailpiece... that might be interesting. But I don't have an itch to try it right now.
Thanks for the input IF! No rush D9... I'm gunna have to go buy some buckets and start playing around. I really want to know what a 3rd bucket would do to this system because I get the feeling it'll explain what the plants do or do not like.
I think I get what your saying and I've tried to illustrate it below. Sounds like a reasonable theory and I buy it. I believe this is the benefit of a flood and drain or ebb and flow hydroponics system. I'm more so wondering what is going on with the lower bucket.
So here is like a comic strip. Top left is beginning and lower right is end.
New water pushes gases down and out of holes on the side of the bucket. Depending on how much water is being added and how quickly, some gas might possibly be pushed down through the tailpiece, but there would be less resistance through the side holes so most if not all of it escapes through there. Fresh gas is
drawn into the bucket and now is when I begin to wonder...
Pulsing the water means less water will attach to the medium and thus more water will end up in the lower bucket. Provided the buckets are sealed, the air in the lower bucket will want to go somewhere else which is really what I was asking about before about gases escaping UP through the tailpiece. But, it dawned upon me now that the gases in the lower bucket could just be pressurized because the resistance to flow through the tailpiece would be too much. I'm thinking the pressured air would then act like a spring, forcing water up the tailpiece thus raising the PWT. Maybe if there was a lot of water already above the PWT, the gas would have nowhere to go and it would have to cause the bucket to expand. If it works like a spring, the rising PWT would also push gases out the side of the holes and out the top of the container. I wouldn't think this would be a good idea because the top of the medium sounds like it is the most dry/air rich spot in the container so many holes on the side might offer less resistance so not much will want to go upwards. Then again, maybe this is a good thing to move nutrient salts around.
If the buckets are not sealed then gases in the lower bucket would just leave through the gap. Maybe this is best because it would keep the PWT more constant instead of the spring (which I'm not sure even works) creating an ebb and flow just for the bottom roots. Didn't you drill some holes in the top of your lower bucket IF?
Like D9 said earlier in this thread, there is now a few of us trying to make PPK into something it is not. It might not be possible for it to produce the largest trees period (like RDWC), but it sure might produce the easiest large trees. Then again, this won't stop me from trying to understand how it works as to make it as efficient and effective as possible if it isn't already.
I think I get what your saying and I've tried to illustrate it below. Sounds like a reasonable theory and I buy it. I believe this is the benefit of a flood and drain or ebb and flow hydroponics system. I'm more so wondering what is going on with the lower bucket.
So here is like a comic strip. Top left is beginning and lower right is end.
New water pushes gases down and out of holes on the side of the bucket. Depending on how much water is being added and how quickly, some gas might possibly be pushed down through the tailpiece, but there would be less resistance through the side holes so most if not all of it escapes through there. Fresh gas is
drawn into the bucket and now is when I begin to wonder...
Pulsing the water means less water will attach to the medium and thus more water will end up in the lower bucket. Provided the buckets are sealed, the air in the lower bucket will want to go somewhere else which is really what I was asking about before about gases escaping UP through the tailpiece. But, it dawned upon me now that the gases in the lower bucket could just be pressurized because the resistance to flow through the tailpiece would be too much. I'm thinking the pressured air would then act like a spring, forcing water up the tailpiece thus raising the PWT. Maybe if there was a lot of water already above the PWT, the gas would have nowhere to go and it would have to cause the bucket to expand. If it works like a spring, the rising PWT would also push gases out the side of the holes and out the top of the container. I wouldn't think this would be a good idea because the top of the medium sounds like it is the most dry/air rich spot in the container so many holes on the side might offer less resistance so not much will want to go upwards. Then again, maybe this is a good thing to move nutrient salts around.
If the buckets are not sealed then gases in the lower bucket would just leave through the gap. Maybe this is best because it would keep the PWT more constant instead of the spring (which I'm not sure even works) creating an ebb and flow just for the bottom roots. Didn't you drill some holes in the top of your lower bucket IF?
I think it does all of those things, but the fundamental aspect of PPK is how the holes allow gases to leave the lower part of the upper bucket. Ya might want to check out the MicroKote to lessen root ringing if it is even much of a problem.
O2 injection can raises DO to a toxic level as well. From what I've learned from the hydro gurus is air bubbles don't absorb into the water, but it is mechanical action breaking the surface tension like with a water fall that allows water to take in O2.
While MrDizzle was playing around with perlite, he learned from a member named Janus that best results were achieved with a constant drip, BUT I believe neither of them used a bottom res of any kind so there system was simply a drip method. This has me thinking that the limitation of PPK is going to be that it won't be possible to pulse as frequently as possible for optimal growth without draining the lower bucket res and recirculating it or running it down the drain. One way to increase the need for more pulses would be to increase evaporation.
Like D9 said earlier in this thread, there is now a few of us trying to make PPK into something it is not. It might not be possible for it to produce the largest trees period (like RDWC), but it sure might produce the easiest large trees. Then again, this won't stop me from trying to understand how it works as to make it as efficient and effective as possible if it isn't already.
Quotes by catman
“I must be really misunderstanding something here.. If no gas goes through the tailpiece? Where does it go? Does it go between the gap in the buckets, outside of the buckets, and comes back in the holes in the upper bucket? I thought the only connection between the two buckets was through the tailpiece. Is the tailpiece not air tight and the air goes up around it? Anyway, I was just thinking that having it sealed would make more gas go up into the medium and it would be simple enough to just apply some tape around where the two buckets meet.”
First I would like to share with everyone the results of the math I did a couple of years ago in order to compare the relative amounts of free o2 in water and air.
It is generally accepted in hydroponic applications that a dissolved oxygen level of 9 mg/l is excellent.
While it is possible to achieve slightly higher levels in some environmental conditions and using more advanced equipment you will still only get a little bit more than 9 mg/l, say 10-11-12 mg/l. This seems to be about the limit with ambient air. You can go beyond this only with pure o2 injection using equipment like a speece cone.
So if we take 9 mg/l in water and convert it to ppm we get 9 ppm as a mg is 1000th of a gram and a gram is 1000th of a liter.
Ambient air is 21% o2 so it is 210,000 ppm.
This makes the content of free o2 molecules in air 23,333 times greater than the free molecules in the same volume of water.
No gas goes through the tailpiece because the bottom of the tailpiece is constantly submerged. The water acts as a barrier to gas flow here.
When the pulsed water hits the top of the medium and falls it is both pushing and pulling air along with it.
The holes in the sidewall do achieve some root pruning but that is not their primary role in this device.
On the down stroke they allow gas to escape the container as downward pressure is presented in the form of falling water.
As the column of water passes the holes it then draws in gases from them.
As the pulse hits and falls it also draws air into the top of the medium behind it.
You can think of the upper container assembly with the tail piece and the sidewall holes as a water and gas separator.
It functions this way because the density, cohesion, and adhesion of water cause it to have a greater molecular friction than air.
This physical fact allows gases to move much easier through the medium than water.
Water continues through the substrate on the hydraulic pathway provided by the tailpiece and the connection to the water in the reservoir while the gas is displaced through the holes and the top of the medium.
There is very little significant gas exchange going on in the lower reservoir container. The lid and the hole in the lid that the tail piece goes through are loose enough to allow slow gas exchange and still have a limiting effect upon evaporation.
So far the entire idea of gas exchange in the reservoir has been a non starter as enhancing it will not achieve a usable increase in o2 in the medium.
I have played around with different tail piece lengths in different iterations but settled on the standard 6” stock one off the shelf at lowes. Works great.
It is long enough to allow a wide range of air gap adjustment and still get the minimum required 2” gap necessary to remove the pwt from the root zone.
“Sounds easy enough, but doesn't manipulating water in the lower bucket also change where the PWT is?”
Yes, it does. The pwt will always exist immediately above the surface of the solid water level inside the reservoir container thus forming the elevated solid water level inside the tail piece.
“I've been thinking along the lines that it would be best to keep the PWT as close to the upper bucket's root mass as possible, but perhaps this isn't a big deal as long as the PWT is always below the root mass.”
This why the water level in the bottom container is adjustable. You can use it to fine tune water content. See the discussions on the controlled water table.
If you were sub-irrigating full time supplemented with an occasional top watering by hand you might want the water level 2” below the upper bucket. This is enough to remove most pwt's from the root zone yet will supply the maximum capillary reach into the medium.
Conversely, if you were to automate and pulse large amounts frequently you may want to drop the water level to reduce this capillary flow as a compensation for the large mass of water coming in from above. The moisture content of the capillary column is not uniform throughout the column. It is dense at the bottom of the column and thins along a gradient curve progressively as you approach the top of the column due to the effects of gravity. This, in turn, allows you to dial in the beginning moisture content by moving the column up and down.
You will find that you might want to adjust it for differing environmental considerations.
“I also wonder if the PWT ever does make its way into the upper bucket the way you do things and if this is actually beneficially. It certainly wouldn't always be there, but would be flooded and drained frequently. Maybe this is why you have water roots to begin with or do you think the plant just has a natural tendency to have water roots no matter what?”
In operation the pwt should never make its way into the root zone. The liquid that would otherwise form it in a standard container just passes by on it's way out.
The plant will try to grow both types of roots if allowed. We must have a hydraulic pathway for this device to work and if water can move up or down so can roots. Using the tail piece we severely restrict growth in that area. The air roots stop at the interface of air and solid water inside the tail piece and some water roots go past it. But not much.
“Do you think you've also significantly regulated timing by experimenting with various medium mixtures?”
I'm not sure what you mean by this.
“Feel free to ignore anything or parts of what I've said for any reasons. I think differently than most people because I was born with a developmental (brain) disability and I'm not a very good communicator. I seem to use a hundred words to say something that only needs three at times. You already invest so much time and energy that I'm grateful for and thanks again for helping me understand PPK better. I'll just have to be more patient until I can do some hands on experimenting myself. I'll be sure to share my trails and errors, and hopefully some success with ya in the future.”
Don't worry about the time involved. This thread is about helping people grow their medicine.
You really don't need to understand this device to build and use it. If you build it and operate it like the people here do you will reliably grow nice, healthy plants with a decent yield.
I think my reply here answers most of the questions you have presented in your second post also so I will not directly address that post unless I have missed something. Please let me know if I have.
d9
__________________
“I must be really misunderstanding something here.. If no gas goes through the tailpiece? Where does it go? Does it go between the gap in the buckets, outside of the buckets, and comes back in the holes in the upper bucket? I thought the only connection between the two buckets was through the tailpiece. Is the tailpiece not air tight and the air goes up around it? Anyway, I was just thinking that having it sealed would make more gas go up into the medium and it would be simple enough to just apply some tape around where the two buckets meet.”
First I would like to share with everyone the results of the math I did a couple of years ago in order to compare the relative amounts of free o2 in water and air.
It is generally accepted in hydroponic applications that a dissolved oxygen level of 9 mg/l is excellent.
While it is possible to achieve slightly higher levels in some environmental conditions and using more advanced equipment you will still only get a little bit more than 9 mg/l, say 10-11-12 mg/l. This seems to be about the limit with ambient air. You can go beyond this only with pure o2 injection using equipment like a speece cone.
So if we take 9 mg/l in water and convert it to ppm we get 9 ppm as a mg is 1000th of a gram and a gram is 1000th of a liter.
Ambient air is 21% o2 so it is 210,000 ppm.
This makes the content of free o2 molecules in air 23,333 times greater than the free molecules in the same volume of water.
No gas goes through the tailpiece because the bottom of the tailpiece is constantly submerged. The water acts as a barrier to gas flow here.
When the pulsed water hits the top of the medium and falls it is both pushing and pulling air along with it.
The holes in the sidewall do achieve some root pruning but that is not their primary role in this device.
On the down stroke they allow gas to escape the container as downward pressure is presented in the form of falling water.
As the column of water passes the holes it then draws in gases from them.
As the pulse hits and falls it also draws air into the top of the medium behind it.
You can think of the upper container assembly with the tail piece and the sidewall holes as a water and gas separator.
It functions this way because the density, cohesion, and adhesion of water cause it to have a greater molecular friction than air.
This physical fact allows gases to move much easier through the medium than water.
Water continues through the substrate on the hydraulic pathway provided by the tailpiece and the connection to the water in the reservoir while the gas is displaced through the holes and the top of the medium.
There is very little significant gas exchange going on in the lower reservoir container. The lid and the hole in the lid that the tail piece goes through are loose enough to allow slow gas exchange and still have a limiting effect upon evaporation.
So far the entire idea of gas exchange in the reservoir has been a non starter as enhancing it will not achieve a usable increase in o2 in the medium.
I have played around with different tail piece lengths in different iterations but settled on the standard 6” stock one off the shelf at lowes. Works great.
It is long enough to allow a wide range of air gap adjustment and still get the minimum required 2” gap necessary to remove the pwt from the root zone.
“Sounds easy enough, but doesn't manipulating water in the lower bucket also change where the PWT is?”
Yes, it does. The pwt will always exist immediately above the surface of the solid water level inside the reservoir container thus forming the elevated solid water level inside the tail piece.
“I've been thinking along the lines that it would be best to keep the PWT as close to the upper bucket's root mass as possible, but perhaps this isn't a big deal as long as the PWT is always below the root mass.”
This why the water level in the bottom container is adjustable. You can use it to fine tune water content. See the discussions on the controlled water table.
If you were sub-irrigating full time supplemented with an occasional top watering by hand you might want the water level 2” below the upper bucket. This is enough to remove most pwt's from the root zone yet will supply the maximum capillary reach into the medium.
Conversely, if you were to automate and pulse large amounts frequently you may want to drop the water level to reduce this capillary flow as a compensation for the large mass of water coming in from above. The moisture content of the capillary column is not uniform throughout the column. It is dense at the bottom of the column and thins along a gradient curve progressively as you approach the top of the column due to the effects of gravity. This, in turn, allows you to dial in the beginning moisture content by moving the column up and down.
You will find that you might want to adjust it for differing environmental considerations.
“I also wonder if the PWT ever does make its way into the upper bucket the way you do things and if this is actually beneficially. It certainly wouldn't always be there, but would be flooded and drained frequently. Maybe this is why you have water roots to begin with or do you think the plant just has a natural tendency to have water roots no matter what?”
In operation the pwt should never make its way into the root zone. The liquid that would otherwise form it in a standard container just passes by on it's way out.
The plant will try to grow both types of roots if allowed. We must have a hydraulic pathway for this device to work and if water can move up or down so can roots. Using the tail piece we severely restrict growth in that area. The air roots stop at the interface of air and solid water inside the tail piece and some water roots go past it. But not much.
“Do you think you've also significantly regulated timing by experimenting with various medium mixtures?”
I'm not sure what you mean by this.
“Feel free to ignore anything or parts of what I've said for any reasons. I think differently than most people because I was born with a developmental (brain) disability and I'm not a very good communicator. I seem to use a hundred words to say something that only needs three at times. You already invest so much time and energy that I'm grateful for and thanks again for helping me understand PPK better. I'll just have to be more patient until I can do some hands on experimenting myself. I'll be sure to share my trails and errors, and hopefully some success with ya in the future.”
Don't worry about the time involved. This thread is about helping people grow their medicine.
You really don't need to understand this device to build and use it. If you build it and operate it like the people here do you will reliably grow nice, healthy plants with a decent yield.
I think my reply here answers most of the questions you have presented in your second post also so I will not directly address that post unless I have missed something. Please let me know if I have.
d9
__________________
Last edited:
Hahaha...
I don't have the same problem as my daughter...My dogs give my underwear a very wide berth.
catman,
Since age has left me semi-retarded, I tend to reduction to understand new concepts. D9 has taken some basic laws of hydraulics and very logically and cleverly put them to advantageous use to simplify creating a moisture and oxygen rich root zone.
As D9 explains, any pot with any medium (with a fine texture) will always have a perched water table because of water's affinity to adhere to surfaces and to itself that will overcome gravity preventing it to drain. While any type of wick will remove the PWT and provide a corresponding capillary action drawing available water, due to the absorbent nature of the media into the pot, all wicks are not equal to that task. A wick using the same material in the pot will be equal. At some point gravity will prevent further upward travel of water and the media above that point will stay dry.
The trick is to use the level of the lower reservoir to keep the PWT ('dead zone' for air roots) out of the pot yet high enough to maximize capillary action creating the largest optimal moisture rich root zone. Roots can go past this pwt but really don't need to spend energy to do so. That the massive tree size and lack of tap/water roots speaks to water needs being easily met in the pot.
In my minds eye, I see this as a slight domed area as the water will want to adhere to the side of the pot while the center is free to rise to it's limit.
I could be full of shit too, but it seems to make sense to me. Food coloring will solve that question.
A pulsed top feed will take care of the dry media letting the roots occupy this area as well as create an ambient air pumping action. Water leaves= air returns. This also leaches unused, unbalanced nutrients from the pot back to the reservoir to be diluted by the constant refreshing that takes place from the float feed tank as the plants use the water/nutes, preventing a toxic media level.
I will surmise, and D9 will correct me if I'm off, that the top feed must be limited to runoff to the rez as not to change the rez level so much as to place the PWT back into the pot.
The biggest surprise to me and probably most others is the stability of the nute solution which acts unlike almost every 'active' system. Lower ec's and proper ph and it pretty much seems to stay in that useful range without messing with it. Jack's hydro must have enough buffers in it to make up for the little the media can provide. I'll again surmise that because it is a closed system, and that there is no organic material (roots, root exudates, light for algae etc.) in the water to feed aerobic or anaerobic bugs to a point of imbalance, much the same principle as water towers in rural water districts have used for hundreds of years.
You're not forcing air into the water to keep roots alive as in R-DWC and changing the water/nute chemistry. Again, lower ec levels are needed because everything the plant needs is available at all times through the wick which probably lessens the Ph/ec swings common in DWC. More with less is good.
I have to admit you lost me a bit with the concept of a hermetically sealed unit. The top feed will add water to the rez and the bit of air would be displaced by increased water volume would just leave via to hole in the lid that the wick passes through. The water level in the rez is always higher than the wick pipe, so air cannot go thru it into the pot.
Same as the S trap in your toilet. The water prevents sewer gas from getting in your house. Sealing the rez airway tight will only allow so much water into the rez and the rest would just fill the media pot drowning your air roots you have worked hard to encourage the plant to make.
Having a porous mix in the pot makes sure that any space that is not filled with water or roots will be filled with air. It has to be. No way to avoid it. Lots of holes in the pot and mix make that exchange to be as free and fast as possible.
Turbo roots. The beauty of air is that if you make a space for it, it will be there. No moving parts required.
I'm just rambling anyway, not really saying anything you didn't already know. I'm really just thinking out loud to see if I got it right .My condensing 161 pages as I understand it. D9 can slap me if I'm wrong.
I have given much thought to how to screw around with and complicate D9's ideas for the simple reason that making 22oz. plants should not be this easy and carefree but apparently it is...
once D9 put more than few good years into learning how things work.
We're pretty lucky that this pro Ganja-man has all this free time to type instead of fiddling with his plants.
Someday there will be an old Granny beating on a DEA screw with her cane yelling
"Gitcher stinkin' hands off my PPK's."
News at 11.
Since age has left me semi-retarded, I tend to reduction to understand new concepts. D9 has taken some basic laws of hydraulics and very logically and cleverly put them to advantageous use to simplify creating a moisture and oxygen rich root zone.
As D9 explains, any pot with any medium (with a fine texture) will always have a perched water table because of water's affinity to adhere to surfaces and to itself that will overcome gravity preventing it to drain. While any type of wick will remove the PWT and provide a corresponding capillary action drawing available water, due to the absorbent nature of the media into the pot, all wicks are not equal to that task. A wick using the same material in the pot will be equal. At some point gravity will prevent further upward travel of water and the media above that point will stay dry.
The trick is to use the level of the lower reservoir to keep the PWT ('dead zone' for air roots) out of the pot yet high enough to maximize capillary action creating the largest optimal moisture rich root zone. Roots can go past this pwt but really don't need to spend energy to do so. That the massive tree size and lack of tap/water roots speaks to water needs being easily met in the pot.
In my minds eye, I see this as a slight domed area as the water will want to adhere to the side of the pot while the center is free to rise to it's limit.
I could be full of shit too, but it seems to make sense to me. Food coloring will solve that question.
A pulsed top feed will take care of the dry media letting the roots occupy this area as well as create an ambient air pumping action. Water leaves= air returns. This also leaches unused, unbalanced nutrients from the pot back to the reservoir to be diluted by the constant refreshing that takes place from the float feed tank as the plants use the water/nutes, preventing a toxic media level.
I will surmise, and D9 will correct me if I'm off, that the top feed must be limited to runoff to the rez as not to change the rez level so much as to place the PWT back into the pot.
The biggest surprise to me and probably most others is the stability of the nute solution which acts unlike almost every 'active' system. Lower ec's and proper ph and it pretty much seems to stay in that useful range without messing with it. Jack's hydro must have enough buffers in it to make up for the little the media can provide. I'll again surmise that because it is a closed system, and that there is no organic material (roots, root exudates, light for algae etc.) in the water to feed aerobic or anaerobic bugs to a point of imbalance, much the same principle as water towers in rural water districts have used for hundreds of years.
You're not forcing air into the water to keep roots alive as in R-DWC and changing the water/nute chemistry. Again, lower ec levels are needed because everything the plant needs is available at all times through the wick which probably lessens the Ph/ec swings common in DWC. More with less is good.
I have to admit you lost me a bit with the concept of a hermetically sealed unit. The top feed will add water to the rez and the bit of air would be displaced by increased water volume would just leave via to hole in the lid that the wick passes through. The water level in the rez is always higher than the wick pipe, so air cannot go thru it into the pot.
Same as the S trap in your toilet. The water prevents sewer gas from getting in your house. Sealing the rez airway tight will only allow so much water into the rez and the rest would just fill the media pot drowning your air roots you have worked hard to encourage the plant to make.
Having a porous mix in the pot makes sure that any space that is not filled with water or roots will be filled with air. It has to be. No way to avoid it. Lots of holes in the pot and mix make that exchange to be as free and fast as possible.
Turbo roots. The beauty of air is that if you make a space for it, it will be there. No moving parts required.
I'm just rambling anyway, not really saying anything you didn't already know. I'm really just thinking out loud to see if I got it right .My condensing 161 pages as I understand it. D9 can slap me if I'm wrong.
I have given much thought to how to screw around with and complicate D9's ideas for the simple reason that making 22oz. plants should not be this easy and carefree but apparently it is...
once D9 put more than few good years into learning how things work.
We're pretty lucky that this pro Ganja-man has all this free time to type instead of fiddling with his plants.
Someday there will be an old Granny beating on a DEA screw with her cane yelling
"Gitcher stinkin' hands off my PPK's."
News at 11.
Keep in mind that the top feed is drawing off the same control as the rest of the interconnected sub-reservoirs. So the level drops as the pulse fires, and then everything drains back into itself.
I actually almost drain the entire bottom of the system while pulsing, then it drains back to equilibrium. (Technically, the float valve opens up for nutes from the bulk reservoir, but it establishes equilibrium fast enough to remain in balance.)
Root exudates are water soluble, and therefore are present in the hydraulic column, and will trend towards equalibirium concentrations in both the solution within the media and the sub reservoir.
As a side note: One thing we aren't really talking about is the microbiology of the media. Insofar as it is a media based root zone, it may in fact have some soil-ish qualities... that is, if our feed rates are below 60ppm P, the root zone may be supporting beneficials... That is, there might actually be the consumption of some of the sugar by the desired little critters. To my knowledge, no one is deliberately running a dead reservoir in this system. Most people are feeding pretty low on the PPM scale... in a manner that would allow for microbial life to contribute something to the system.
Makes sense now knowing that the reservoir level should always be higher than the tailpiece.
A question I'm still asking myself is WHY did you find that pulse feeding creates better results. I'm sure you would agree that running water quickly through a plain bucket with holes in the bottom with mediums that you are using means more water drains out that bottom and less water is adhered to the medium. So, watering large amounts, quickly lessens moisture levels which is why you have to water frequently. Do you think that large amounts of water at once forms a blanket of water that covers the entire circumference of the container forming a seal that pushes down like a piston? That is, when the pulse begins, do you start to see water actually sitting on top of the medium because it can't drain fast enough? I believe I've seen this hand watering perlite when I'm watering quickly during a flush.
Watering frequently, however it is done seems to equal better growth, but I've fallen into a pitfall thinking this is because of increased oxygen. I've seen those numbers before about DO percentages and limitations, but I really needed to be reminded of them. The mediums you use supply enough oxygen provided they are not flooded with stagnant water. So better growth might simply comes from a constant moisture level.
So, this leads me to question the need of the holes in the upper bucket. I wish I could see all of your images becuase correct me if I'm wrong, but you didn't have side holes in the beginning of this thread and you still got great results when you used those large ~20 gallon containers with the bucket inside of them. Being capillary action will only climb so high, wider containers allowed for you to store more solution. If you used buckets with holes in them and in the ~20 gallons, did you ever have watering coming out of the holes? They would seem to serve the same purpose as they do in hempy buckets in this regard. With your current design, do you have ever have water overflowing through the side holes in occasions when the PWT gets too high? Maybe you've got everything dialed in, but if you did over-water, those holes would be a fail-safe, no? Did you stop using the ~20 gallon containers becuase of excessive evaporation (which would increase salt concentrations and pH fluctuation) and/or so that you could pulse feed more often?
Without any holes and in a container with no drainage. I see when I add lots of water quickly and after it drains to the bottom, I can see air bubbles float to the top. Maybe quicker is better because less contact with the blanket of water means more (and/or less confused) air roots.
So, maybe the primary advantage of the side holes isn't related to gases at all and perhaps they serve the purpose of more evenly disturbing nutrient salts. I use Fox Farm's entire line and their powder nutrients make water turn colors so it looks like kool-aid. Perlite might not allow nutrients inside of its pores, but when I water quickly, the next day I can see the colored salts sitting on top of perlite chunks even at the top of the container. If there were no side holes, the blanket or seal of water would move down slowly because of gases resisting it until the gases come under enough pressure to form bubbles to float to the top. This extra contact time with the medium perhaps would leave more salts behind. Having holes, the blanket or seal will fall quicker as gas is displaced out of the holes, but WHY would quicker be better pertaining to salts?
I've been looking through scientific articles on hydro and I learned that some plants grow better depending on the pressure of the medium. This would explain in part why certain strains thrive around different parts of the world and I think this could possibly be the key advantage of RDWC. Maybe the pulses are beneficially becuase they cause periods of increased pressure.
I have played around with different tail piece lengths in different iterations but settled on the standard 6” stock one off the shelf at lowes. Works great.
Yes, it does. The pwt will always exist immediately above the surface of the solid water level inside the reservoir container thus forming the elevated solid water level inside the tail piece.
I was already thinking a longer tailpiece would be best, especially for a beginner like me.
I'm nit-picking words here, but correct me if I'm wrong. The PWT doesn't exists immediately or at the level in the reservoir container. The PWT will be a few inches above the res depending on the size/texture of the medium because smaller particles allow for greater capillary action(and/or surface tension, adhesion, and cohesion)
I revisited page 1 again about CWT, but I still have this pressing question.
I understand that adjusting the water level in the bottom bucket will adjust the PWT and thus adjust water content/moisture, but do we not desire a fixed PWT once the roots are established? Is the consistency of the PWT more or less important than frequent pulses? If the PWT drops below the optimal level, you will have less moisture in the medium, more salt build up, but then the pulse comes and fixes that. I just don't see how you can keep the soil optimally moist at all times without a continuous drip or very frequent pulses either be recirculated, or wasting a lot of water and nutrients.
Couldn't it be said that the air roots are drowned and die when you say they are stopped? I'm just getting hung up that the theory is to never have the PWT high enough so that water roots never form so why not stop any roots from entering the top of the tailpiece with screens on both ends of the tailpiece? Have you ever experimented with no screens at all, allowing for water roots to fill in the lower container?
If you used a very coarse perlite in the tailpiece, the PWT would be higher allowing more room in the bottom bucket for water than if you used chunky perlite. More room in the bottom bucket means you could pulse feed more often. You've played around with lots of mediums for different reasons, but I was wondering if your main objective has ever been to use the medium to regulate the timing of equilibrium? Coarse perlite holds and wicks more water than chunky, but does it too much water (and thus not enough oxygen?) I think I read you've moved to larger sized mediums which suggest the PPK is evolving closer to a drip system.
From what I've seen, the most success from drip systems comes from constant dripping of smaller amounts of water which can be fed from gravity so no need for timers or pumps. If this proved to be most effective, side holes wouldn't be needed and the fundamental benefit of PPK would have to only be the tailpiece/sump/control-over the PWT.
I would say this thread is more about helping people effectively and efficiently grow their medicine. I would stick with soil if I didn't have a low plant count and strains that help me the most are not big yielders.
I really enjoy picking apart systems, ideas, theories, etc.. but I should save more of my breath about the near future. So, I'll tell you about what my environmental conditions are going to be like and we can go from there. I'll be picking this all up very soon. A 4x4x6.5' tent with a vertical 600w on a dimmable ballast. With only 3 plants, I will have to do some topping and LSTing to create lots of bud sites and I'm going hydro primarily to speed up veg time and so that I can reuse medium (I'd like to avoid the hydro store.) Humidity is also very low, 15-30% so perlite should help with that. 6.5' is a lot of headroom for a single 600w so I think I could use 5 gallon pails stacked on top of each other. My goal would be 1g/w so I'm sure I don't need 5 gallons, but I was thinking they could speed up veg time. I won't need to be away from my garden so smaller containers wouldn't be an issue either. I'm gunna go shopping and see what I can find that would work. Thanks again for the help.
Hiya Mr Creosote
That all made sense to me as well. The bitch for me is I literally do not have a minds eye which is why I have to understand things in words and concepts.
I believe this would be true in theory, but I just can't imagine it so easily achievable with timing pulses that the PWT never enters the top-bucket. I'm not even convinced this would be a bad thing and it seems like it might be happening sometime with D9's buckets if he is getting water roots.
Lower EC levels are used in RDWC and hempy buckets as well. I believe there is less pH/EC swings because D9 doesn't need to change his res often like a DWC system. The pulses bring in adjusted water and as long as he isn't feeding more than the plant needs, everything is grand. Less, more often; is what makes hydro better than soil.
What hole in the lid? You mean, just through the wick/tailpiece? I believe the air is just displaced through the gaps around the circumference of where the two buckets meet.
I'm obviously a little loss myself, but I was thinking that in a sealed rez, water would be pulled down until the air is compressed to the point at which it will push back, like a fluid-spring. There would be a limit in which the compressed air would either make the bucket expand or it would fill the media pot like you said.. but, there are those side-holes for water to run out of which lower the PWT like a typical hempy bucket.
The S trap in the toilet is a perfect analogy.
If that was rambling away then I must ramble out of control
FWIW, I think you nailed everything except for an insignificant detail of where the rez air goes once more water fills it.
Could you please make a picture of this IF? This sounds like a recirculating system to me.
I just got back from visiting Lowes and Home Depot. I didn't realize the actual part is really called tailpiece, doh! I could only find 1-1/4'' x 2ft PVC that was closet to it. I wonder if the AMAZING GOOP Plumbers addition would hold it into place or should I really have some sort of lip on the top of the piece? When I go back, I'll see if I can't just find the actual pieces.
There wasn't any 3 gallon pails at either place. I found a 28 quart (7 gallon) rubbermaid trash bin that fits into a 12 quart (3 gallon) version with at least 6'' for the piece. They aren't round, but my plants aren't going to be either. About $10 for the pair though. They seemed sturdy to me, but I hate to take a risk not using the tried and true 5 gals.
I'm thinking of just using 5 gallons with a smaller container or whatever I can find to rest the top one on the bottom. Only about $5 for two 5 gallon buckets.
Could not find shit for medium at Lowes or HD. I have a local distributors who sells Turface by 50 pound bags. They have the MVP, PRO LEAGUE, and QUICK DRY versions. D9, do you think I would have to do any screening of MVP if I was to mix it 1:4 with perlite? I can easily hand water once a day. So Turface wicks better so I'd probably want to use more of it towards the bottom and especially in the wick. A while ago you commented on perlite cultured plants having nute burn and you were wondering why that is.. There is a thread on IC somewhere explaining how nute burn is actually from plant cells growing too fast. I won't be using Jack's so the perlite's lack of CEC will give me more margin for error with Fox Farm's line.
Man, I'm dizzy.. you think the indexes that IF and zeke put together would be helpful for me, but they just get me opening window after window until I forget what I was doin
That all made sense to me as well. The bitch for me is I literally do not have a minds eye which is why I have to understand things in words and concepts.
I believe this would be true in theory, but I just can't imagine it so easily achievable with timing pulses that the PWT never enters the top-bucket. I'm not even convinced this would be a bad thing and it seems like it might be happening sometime with D9's buckets if he is getting water roots.
Lower EC levels are used in RDWC and hempy buckets as well. I believe there is less pH/EC swings because D9 doesn't need to change his res often like a DWC system. The pulses bring in adjusted water and as long as he isn't feeding more than the plant needs, everything is grand. Less, more often; is what makes hydro better than soil.
What hole in the lid? You mean, just through the wick/tailpiece? I believe the air is just displaced through the gaps around the circumference of where the two buckets meet.
I'm obviously a little loss myself, but I was thinking that in a sealed rez, water would be pulled down until the air is compressed to the point at which it will push back, like a fluid-spring. There would be a limit in which the compressed air would either make the bucket expand or it would fill the media pot like you said.. but, there are those side-holes for water to run out of which lower the PWT like a typical hempy bucket.
The S trap in the toilet is a perfect analogy.
If that was rambling away then I must ramble out of control
FWIW, I think you nailed everything except for an insignificant detail of where the rez air goes once more water fills it. Could you please make a picture of this IF? This sounds like a recirculating system to me.
I just got back from visiting Lowes and Home Depot. I didn't realize the actual part is really called tailpiece, doh! I could only find 1-1/4'' x 2ft PVC that was closet to it. I wonder if the AMAZING GOOP Plumbers addition would hold it into place or should I really have some sort of lip on the top of the piece? When I go back, I'll see if I can't just find the actual pieces.
There wasn't any 3 gallon pails at either place. I found a 28 quart (7 gallon) rubbermaid trash bin that fits into a 12 quart (3 gallon) version with at least 6'' for the piece. They aren't round, but my plants aren't going to be either. About $10 for the pair though. They seemed sturdy to me, but I hate to take a risk not using the tried and true 5 gals.
I'm thinking of just using 5 gallons with a smaller container or whatever I can find to rest the top one on the bottom. Only about $5 for two 5 gallon buckets.
Could not find shit for medium at Lowes or HD. I have a local distributors who sells Turface by 50 pound bags. They have the MVP, PRO LEAGUE, and QUICK DRY versions. D9, do you think I would have to do any screening of MVP if I was to mix it 1:4 with perlite? I can easily hand water once a day. So Turface wicks better so I'd probably want to use more of it towards the bottom and especially in the wick. A while ago you commented on perlite cultured plants having nute burn and you were wondering why that is.. There is a thread on IC somewhere explaining how nute burn is actually from plant cells growing too fast. I won't be using Jack's so the perlite's lack of CEC will give me more margin for error with Fox Farm's line.
Man, I'm dizzy.. you think the indexes that IF and zeke put together would be helpful for me, but they just get me opening window after window until I forget what I was doin
Um... My current version is. Puts, to use your terms, a 'blanket' of water across the top of the media, and then drains through the upper bucket, into the lower bucket, then back to the control bucket where my pump lives until everything is even again. When that solution level drops from plant uptake, the float valve maintains the level.
That's fine. Once I reinforced the top of some shallow totes, and used those as sub-reservoirs to fit into a lower ceiling space.
Some thoughts for you my catman:
Perched Water Table is a function of the solution adhering to the media surface with enough force that gravity can't pull it out. There may be a soggy bottom for a minute, but that will by the forces of glorious nature be pulled out and down by the same forces that pull the solution up the wick.
Air roots can hold their breath for a minute or two. Lots of plants get rained on, and don't die. Its when they are continuously submerged that it becomes a problem. And fluctuating PWT levels generate that state. So you move the PWT out of the root zone, and even if it moves a bit, it never submerges the predominant root mass of the plant.
Another thing that keeps catching my eye: My lower reservoir is not air tight. Its a bucket with a lid with a hole in the lid. The 'tailpiece'/'sump' goes through that hole... but there's some play. While it should reduce the effects of evaporation, it doesn't prohibit air exchange and pressure balancing between the lower bucket and the outside air.
...So, you have no mind's eye...
What's the best way for us to communicate with you? I noticed you draw pictures. I can't do that easily, but I might be able to find pictures in the thread that clarify your questions... if you think that will help.
Ah, ha. So, when your float valve is triggered, the system pulses. You do not have your top feed being ran by a timer that pulses with another time device?
I use the term 'blanket' not just to mean water simply falling down through the medium. If the majority of the water comes from say 4 dripper in 4 corners, the middle of the medium will largely be missed by the pulse though of course moisture will move from the 4 corners inwards. But, if A LOT of water comes out at once where you can actually see a pool of water forming on top of the medium before it goes down, that is what I mean by a 'blanket.' A seal that works like a rod and piston. As I've said before, I've just seen 1# trees grown in gravity fed,continuous,drip systems in a simple bucket with all perlite or hydrotron. I'm just trying to figure out if and why pulsing works better and though pushing down the gases with a 'blanket' makes some sense, my intuition strongly suggests it is because you more water to not adhere to the medium so that you have more in your bottom rez to pump back into it.
I think I'll do this then, thanks.
I totally understand this probably more than what is needed. Hydrogen is very unstable and thus it bonds to oxygen molecules which creates surface tension, adhesion, cohesion, which manifest as capillary action.
I follow ya. I'm just wondering how often do you think the PWT moves into the root zone on occasion? Once a month by a freak accident or several times daily?
I understand this now as well.
None at all. I can't see animations or even colors in my mind's eye. This is why I'm trying to understand things with laws of thermodynamics-fluid-dynamics because I have a background in engineering.
Knowing your system recirculates I now understand how yours works. It is like the first picture of a bucket I posted in this thread, but I understand it would be good to keep an external rez away from the heat of the lights and so that it can be larger to serve as a buffer.
I'll do some more digging through your threads and pictures as you've already been helpful enough. Thanks man, I really appreciate it.
No.
My pulse is on a timer.
It moves solution from the control bucket to the top of the plant. This drops the level of the solution in control, and because it is connected to the lower reservoir, that level also drops.
As the solution drains through the plant, it returns to the lower reservoir, which is connected to the control with a 1/2" line from the bottom, allowing the buckets to regain a balanced level. If that level is below the level set by my float valve, my bulk reservoir tops it off, maintaining my controlled air gap.
My pulse is a 'blanket' in your terms. I understand how you are using that term, and I am telling you that my pulse results in an inch of standing water over the entire surface of the media, that then drains down and through the media generating a 'plunger' effect.
In my mind, the PWT refers to the level wherein a solution will no longer drain from a given media do to the fact that 'pulling' quality of capillary forces exceed their opposite (gravity). It does not mean a 'wet spot' to me.
At some point, there may be a wet spot. But because the air gap is controlled, the PWT that is defined by the caplary dynamic does not enter the media. In fact that same capilary dynamic moves the 'wet spot' out of the rest of the media, and down to the PWT. It stays in the 'tailpiece'/'sump', right where we put it. This is good in theory, and confirmed by observation.
If the air gap is not controlled do to float valve failure or something else, then sure, shit might happen.
But in an operating system, the PWT does not move in a meaningful way, unless you adjust your float valve in the control.
