RDWC build

[Ole MacDonald]

This is an RDWC build for 36 plants, modeled after BigToke's design, but with some changes. Clay pellets instead of lava rocks in the net pots. The lava rocks will sit in the reservoir beneath the "waterfall," and there will be air pumps. Also, instead of raising the buckets up, they will sit on the floor. This will make the design easier to use in rooms with low ceilings.

Also, all pipes (supply and drain) will sit on the same side of the buckets leaving more space in the walkways. There will be two pumps sharing the responsibility of moving water, to prevent a standstill in the event one pump fails.

Props to BigToke and everyone else who has taken the time to help us all build better systems!!!

 

[Ole MacDonald]

Q-Max fan pulls air out of box, which pulls air from the room through three 8" ducts that can connect to lights during warmer weather. The window box has a curtain on the inside that lays over several big expanding foam lines to mimic the natural curvature of a curtain, while keeping it stationary as air passes by it. From the outside, the window looks totally normal, is silent, and odor-free.

 

[Ole MacDonald]

Phantom digital ballast plugged into 240V relay, one hp chiller, and the basic bucket layout.

 

[olddirtybastard]

your electrical work is getting me hard. dunno why you would need the clay rocks though, i started with hydroton too but ditched it, plants are better off for it if anything.

definitely a bitch to have to clean out the roots and reuse, or buy new clay and have to clean/prep it anyway, go mediumless

 

[noyd666]

nice clean build there mate.plenty of doo.

 

[Ole MacDonald]

Six 70 liter pumps and one 110 liter pump. Each of the 70 liter pumps will run 6 airstones, one for each bucket. The 110 liter pump will run an 8" disc airstone, which will sit directly under the basket containing the lava rocks and biofilters. The basket will be half submerged, with the waterfall will fall onto the lava rocks. I may have overdone the dissolved oxygen on this one, but is there really such a thing???

I chose to move the lava rocks to the reservoir, because I didn't like the idea of cleaning roots out of the lava rocks or throwing that stuff away each rotation. I do have one question for the brilliant minds on here though:

Q: How will moving the "home" for the beneficials effect colonization? [BigToke's system had the lava rocks in direct contact with the roots.]

The design here was modeled after biofilters in fish tanks, and my reasoning stems from the fact that beneficial fungi don't do much in hydroponics. My goal in using beneficials here is solely to keep bad blooms from happening. Any feedback on this is greatly appreciated!!

 

[Ole MacDonald]

your electrical work is getting me hard. dunno why you would need the clay rocks though, i started with hydroton too but ditched it, plants are better off for it if anything.

definitely a bitch to have to clean out the roots and reuse, or buy new clay and have to clean/prep it anyway, go mediumless

Not to sound completely ignorant, but how would a mediumless DWC system work? It sounds amazing! What holds the root system in place, and how does the plant stay upright?

Thanks for the ideas!

 

[Ole MacDonald]

So the basic design is this: [if you have seen BigToke's Bio Buckets, much of this will look familiar]

Six rows of six buckets each. Every couple rows will drain into a single 4" PVC pipe and return immediately back to the reservoir. There will be six 1.5" PVC pipes that will bring water separately to each buckets. Each bucket will have its own shutoff valve.

This system differs from the Under Current systems in that each bucket is getting water straight from the reservoir, and all water leaving each bucket goes straight back to the reservoir. I don't like the Under Current system design as much, because they run their buckets in series. Here are what I believe are some drawbacks to their design:

(I have never used one of these systems myself, so please correct me if I am wrong)

1. If you need to stop water flowing to one bucket, you have to stop water flowing to all buckets.

2. As water travels from one bucket to the next, temperatures increase and dissolved oxygen decreases. (warmer water holds less oxygen)

3. It is harder to move buckets around, although the uni-seals are pretty cool. Also, you have to drain a bucket before you can move it. Since they are all connected at the base, if you drain one, you drain them all.

4. If for some reason the system clogs, several buckets are affected instead of just one.

Also, if there is ever a leak in the system, because their drain line is at the bottom of the buckets, roots can dry up. In the design I am building, both supply and drain lines run to the top of the bucket. So, even in the worst case scenario imaginable...

Power goes out,
Drain lines spring a leak,
Supply lines also spring a leak,
and both pumps fail simultaneously,

... even if all this happened at the same time, the roots would still be in water, and you could recover them. Yes, they would not be happy, but they would be alive.

(again this idea also came from BigToke's Bio Buckets thread)

In BigToke's design, he ran a drain line between two rows, and ran two supply lines on the outside of the two rows. I have low ceilings in this room, so the buckets are sitting on the floor. I chose to run the supply lines in between the two rows, along side the drain line, to help keep the walkways clear.

I also added air stones, where BigToke had none. He said this was unnecessary, but I believe it will increase the dissolved oxygen in the system. Unfortunately, I do not have an oxygen meter, or I would test the difference. For now, I decided to put them in because they were cheaper than an oxygen meter, and they can't hurt.

The reservoir sits two feet below the floor, and the drain water falls back into the reservoir through a basket containing lava rocks and biofilters.

Now here is where I am conflicted and undecided. I cannot decide whether to run sterile or run beneficials. BigToke's lava rock stuff is really cool, and I like the idea of running beneficials. Snype has some really cool stuff on using bleach, and he has some of the best looking root pictures I've ever seen. I guess the only way to decide is to try different methods and see how long I can go without needing a reservoir change out. I would welcome any informed feedback on this decisions too!!! I have been obsessing over it for weeks now.

(Of course if the decision was made to run sterile, I would not include lava rocks and biofilters.)

Two 2250 GPH pumps will send water to the buckets. I opted to do this, instead of one bigger pump, in case a pump failed. At least some water would still be moving through the system instead of none. There will of course be backflow prevents for both lines before they merge.

I think that sums up the basic idea. I have just now started construction and still am open to new ideas. This should be fun!!

 

[olddirtybastard]

i used lids for my buckets that had support built into the lid so i just drop the rooted clone in the bucket and tie it to the supports (made out of pvc). never clean clay rocks again

Man you got a water chiller you could definitely go the beneficials route, the only time problems come up in these systems is if the temps get too high, or if there is not enough water exchange/aeration. I used to only change the res once a grow using floranova, just kept my temperature under control(no chiller) and had lots of water movement.

 

[DamnUglyDogE]

Well someone has been doing their homework... Solid!!!
Grabbing a bucket and a jar for this show...

Looking great, Ole MacDonald...

 

[5th]

I'm gonna stick around for this also. Good luck.

 

[Ole MacDonald]

Hey great!! Very glad you guys are interested! Thanks for checking it out!

 

[Ole MacDonald]

Drainage and supply lines are done. Holes are drilled in drain pipe.



I was walking through Home Depot and changed my strategy on filtering particulate matter when I saw these 4" drain sleeves!

 

[noyd666]

keeping busy, nice job.

 

[overbudjet]

Imho those air pump are useless with a waterfall setup! If you keep them be sure to intake your air from a clean and cool place.Really nice and clean room old mac!

 

[BreezeEazy]

Imho those air pump are useless with a waterfall setup! If you keep them be sure to intake your air from a clean and cool place.Really nice and clean room old mac!

^agreed. The waterfall + water changes in the bucket will be enough like big toke said. However, I'll be building onto this concept. I know big toke doesn't run he feed lines to the bottom of the bucket but I've seen people do it and I feel it is better because it'll push old water out as new water comes in. The problem with this would be potential siphon effect but one guy drilled a hole into the top of the elbow in the bucket. This is where I plan on improving it but making that hole not only a preventative siphon hole but turning this hole into a venturi valve. I don't see how it could hurt.

I'm right there with ya though. I'll be building a bio-bucket system in the next month, currently 2 weeks out from a soil harvest. I also had the idea of adding stones to the main res for increasing benies, I'll probably even pre-load them by letting them sit in my vortex brewer when making a brew.

The only thing I'm stuck on is what to use for my feed and drain lines. Will pH negatively effect my lines? Do I need food grade? I want something I can put a clamp on. I also need a way to remove buckets so I can veg in a different room so I can be perpetual. Sadly, I think PVC shut off valves are my best bet but they get $$$ quick.

 

[Depth.Charge]

^agreed. The waterfall + water changes in the bucket will be enough like big toke said. However, I'll be building onto this concept. I know big toke doesn't run he feed lines to the bottom of the bucket but I've seen people do it and I feel it is better because it'll push old water out as new water comes in. The problem with this would be potential siphon effect but one guy drilled a hole into the top of the elbow in the bucket. This is where I plan on improving it but making that hole not only a preventative siphon hole but turning this hole into a venturi valve. I don't see how it could hurt.

I agree about building onto the concept and running feed lines to the bottom. No need for an anti-siphon hole, just use a check valve directly after the feed pump, problem solved. Venturi is a great idea, many pumps out there with venturi built in. Keep growing.

 

[Ole MacDonald]

Imho those air pump are useless with a waterfall setup! If you keep them be sure to intake your air from a clean and cool place.Really nice and clean room old mac!

That could be the case! Thanks for the compliment Overbudjet.

I thought a lot about BigToke's suggestion that air pumps would do no good at all in the system. Here is why I respectfully disagree:

The roots are using oxygen in each bucket. I wanted my dissolve oxygen levels to stay at saturation levels in each bucket. For 66.5 degrees Fahrenheit (19 degrees celsius), DO saturation level is 9.26 mg/L.

http://www.dnr.mo.gov/env/esp/wqm/DOSaturationTable.htm

If we assume that the water fall is capable of reaching maximum saturation level in the reservoir, then we can also assume water entering each bucket will be close to the same. But since the massive root systems are using oxygen in each bucket, and oxygen is not being added to the buckets, I believe saturation levels cannot be maintained in the buckets themselves. Since the reservoir is the place where oxygen is replenished, and the buckets are where the oxygen is used, I think the reservoir is the only place saturation level could be maintained.

Now I am no scientist, so I have no idea how much DO levels drop in each bucket as the oxygen is used (not to mention evaporation) before the water returns to the reservoir. I just know if oxygen is being removed from the water in each bucket, and it is not being replenished in the bucket, then the levels are dropping some.

There is something to be said for the constant flow of newly oxygenated water into the buckets, but even BigToke's design changed out water only 7 to 10 times an hour, according to his math. This design will exchange water at about the same rate, after loss and inefficiencies are taken into account. It is also very possible that the loss of oxygen in each bucket is negligible. I just have no way to measure these things.

One day, I would really like to get an oxygen meter and run a test running just the waterfall, just airstones, and with both. You are probably right Overbudjet, and these airstones are probably unnecessary for this system to run successfully.

But they sure do make pretty bubbles.

 

[BreezeEazy]

I agree about building onto the concept and running feed lines to the bottom. No need for an anti-siphon hole, just use a check valve directly after the feed pump, problem solved. Venturi is a great idea, many pumps out there with venturi built in. Keep growing.

Yeah I'm looking at the supreme mag-drive 1800. Might have to get a check valve just to be safe.

There is something to be said for the constant flow of newly oxygenated water into the buckets, but even BigToke's design changed out water only 7 to 10 times an hour, according to his math. This design will exchange water at about the same rate, after loss and inefficiencies are taken into account. It is also very possible that the loss of oxygen in each bucket is negligible. I just have no way to measure these things.

What do you think about my idea of adding a venturi valve to every bucket intake? It is pretty easy to do. I got the idea from an aussie who did it for his aquaponics.

 

[Ole MacDonald]

Yeah I'm looking at the supreme mag-drive 1800. Might have to get a check valve just to be safe.



What do you think about my idea of adding a venturi valve to every bucket intake? It is pretty easy to do. I got the idea from an aussie who did it for his aquaponics.

Well, I'm all about adding things that are cost efficient, but I don't see the benefit here. I have a very consistent flow rate to each bucket with this design. What would the venturi valve do?