passive plant killer

[jjfoo]

I guess part of my confusion is that I am reading how the elements a plant need are taking up by the plant by releasing hydrogen ions through a proton pump (http://en.wikipedia.org/wiki/Proton_pumps) from the roots, which cause the the cation exchange process. I am reading that plants get stuff via osmosis and also am reading that they get the salts via the cation exchange process.

Basically, if I had to sit down and explain how water and nutes make it from the soil up the plant, I wouldn't be confident to say it is simply osmosis, but I am lacking something in my mental model becaues I'm not really sure what fully goes on.

So as far as my question about selective uptake, I'm now thinking they take up different cations and he pH affects this.



see: http://en.wikipedia.org/wiki/Plant_nutrition

"Plants uptake essential elements from the soil through their roots and from the air (mainly consisting of carbon and oxygen) through their leaves.
Nutrient uptake in the soil is achieved by cation exchange, where in root hairs pump hydrogen ions (H+) into the soil through proton pumps. These hydrogen ions displace cations attached to negatively charged soil particles so that the cations are available for uptake by the root."

 

[jjfoo]

I know there's a lot I don't understand. But that's probably better than not knowing that I don't understand.

yea, I'm with you on this

I'm not into the whole ignorance is bliss way of thinking

keep in mind that the map isn't the teritory
( http://en.wikipedia.org/wiki/Map–territory_relation )

I mean science is based on models that are flawed but are open being improved as we have more data.


maybe this will help:

http://www.biol.sc.edu/courses/bio102/f97-3233.html

When I was a kid I learned that an atom was a nucleus being orbited by electrons. I even saw drawings of this. That model has some serious flaws, but also has value, for what it is, basically a simple model.

If you practice science you will take the stance that nothing can be known for certain. You can't really prove that something causes something else with %100 certainty. However you can absolutly disprove things, which has great value.

 

[ImaginaryFriend]

Those links are beyond my pay grade.

I'll spend a bit of time with them after work...

Is osmosis fundamentally different or exclusive from cation exchange?

(Cation exchange is another mystery to me... I just know I have to pour some nutes through coco to prep the media before transplanting if I want there to be calcium available.)

 

[*mistress*]

water movement & nutrient absorption...

water movement & nutrient absorption...

maybe plant takes up water differently than taking up nutrients...

maybe.....
cation exchange maybe exchange of ions. osmosis maybe ability of cation exchange to take place, w/in pressure inside & outside of plant. ph avialability (solubility) of nutrients during process of cation exchange...1 plant can transpire gallons of water a day.

water movement, generally... generic plant physiology. for entertainment education only.

"roots anchor the plant, absorb water and minerals from the [media], and store food produced in leaves and the green stem.

leaves and water loss
ninety percent of the water that enters the roots is lost as water vapor., most of it through open stomata in the leaves. the process by which plants lose water is called transpiration.

how can plants survive losing so much of their moisture?
the answer is that water lost through the top of the plant is continuously replentished from the roots below.

several forces are involved in the movement of water in plants. osmosis continually pulls water into the roots, building up internal root pressure, that pushes water into the stem.

in addition, xylem cells form long narrow tubes, and the water in these tubes is attracted to the xylem cell walls. this attraction tens to pull the water up the walls. the force of attraction that causes water to move up narrow tubes is called capillary action.

however, the major force behind the movement of water in plants is the attraction of water molecules for one another. the upward movement of water molecules tugs on the molecules below. each water molecule that evaporates from a leaf exerts a pull all the way down to the roots. the loss of water from the leaves thus helps maintain water flow throughout the plant.

plants benefit from transpiration in many ways. it prevents the accumulation of excess water in the plant body. the evaporation of water from the leaves cools the plant, much as evaporation cools animals. transpiration also creates a force that results in the steady supply of water to all the plant organs."

hope this helps

 

[ImaginaryFriend]

1 redwood can transpire thousands of gallons of water a day. this does not mean that the plant is taking up thousands of gallons of nutrient solution, as they rely on forest humus & mycorrhyzae & microbes & old rock deposits for mineral nutrition...

But what if we were growing redwoods in a dead-reservoir RDWC?

 

[*mistress*]

maybe, the microbes will find the plants' roots. maybe, plants' roots desire ph-balanced nutrient solution. more water than nutrient solution.

water add-backs... if recirculate...
feed-water-feed....if dont recirculate. end.

in imagination. tomatoes, squash, orchids...
*edit*

Those links are beyond my pay grade.

I'll spend a bit of time with them after work...

I do this kind of thing at my day job and could do a lot of this on my own, but would want to collaborate with someone on how to hook up large amounts of wires to the limited general purpose i/o pins (GPIO).
I have no expr building a multiplexer, so I would need help.

Any geeks out there interested in collaborating do something like this?

 

[delta9nxs]

fascinating discussions going on here.

i'll try to catch up later. i'm too tired now. just spent all day whacking another one.

also, just for the record, i wanted to announce my new heaviest plant. last week's plant, bud cake, weighs in at 569 grams or 20.07 oz's. it overfilled the 2.5 gal container and bud had to be pushed down a little to get the lid on.

the one i whacked today is close but i don't think it will be quite as large.

well i'm loading up a big bowl of dry kief, scissors hash, and ground bud, as much as i can get in there, and going to bed.

later on

 

[ImaginaryFriend]

My question to you was "What if we are growing redwoods in a RDWC with a dead reservoir."

I'm hypothesizing that in the absence of a biological intermediary, we can understand nutrient uptake simply in terms of mechanical forces as noted in the VPD discussions. An example where this (absence of a biological intermediary) might be applied is in a edit: DEAD Deep Water Culture system.

In an living organic system, the nutrient building blocks stored in humus and mineral concentrates are mediated by mycorrhyzae and a legion of microbes. This interface dictates the nutrient concentration/availability at the root walls (where the osmotic process takes place). As the redwood sucks up thousands of gallons of water, it is not sucking up thousand gallons of nutrient solution because 1. of the microbial population, and 2. it is not growing in a dead reservoir nutrient bath.

But, I ask you, "What if it was?"

I propose that the process related to nutrient uptake in a living media is fundamentally different than the nutrient uptake process when those nutrients are supplied in a dead reservoir because of the action of the living microbes.

I propose that it is this organic mechanism you seem to be talking around when you say that water uptake and nutrient uptake are different processes, without ever explaining how you think it happens.

In the absence of microbes (like the very popular dead reservoir high flow Recirculating Deep Water Culture systems found on other forums), we can understand nutrient uptake in terms of hydraulic force, osmotic force, and trending to equilibrium as it relates to a semi-permeable membrane.

When you add living things... well, you've added living things and there aren't really any good rules for things that are alive...

 

[ImaginaryFriend]

also, just for the record, i wanted to announce my new heaviest plant. last week's plant, bud cake, weighs in at 569 grams or 20.07 oz's. it overfilled the 2.5 gal container and bud had to be pushed down a little to get the lid on.

You are a magic man. Just over a year later... and 250% yields.

 

[jjfoo]

In the absence of microbes (like the very popular dead reservoir high flow Recirculating Deep Water Culture systems found on other forums), we can understand nutrient uptake in terms of hydraulic force, osmotic force, and trending to equilibrium as it relates to a semi-permeable membrane.

I thnk you are leaving out the cation exchange process which is a big part of nute uptake.

Microbes break down organic matter into stuff the plant can use. Conventional nutes can be used right out of the bottle.

Many people use both, living soil with the addition of conventional nutes.

 

[ImaginaryFriend]

That's cause I have no idea what it is...

In practice, it is managed by pH... right?

And it's relatively quantifiable?

 

[dmoose]

I really like the idea of the MF Wick, and seems to to be working pretty good on my test. Can someone explain the benefit of a Media Wick vs. MF Wick? Any observations so far? With the addition of a Top Feed, wether pulse or whatever, how much difference does the type of wick make?

 

[oldone]

I really like the idea of the MF Wick, and seems to to be working pretty good on my test. Can someone explain the benefit of a Media Wick vs. MF Wick? Any observations so far? With the addition of a Top Feed, wether pulse or whatever, how much difference does the type of wick make?

Hi dmoose. I used a microfiber wick on my first ppk run. I found a lot of roots growing into the rez. A media wick may prevent that from happening. Check out my root porn here. I experienced weird ph/ec fluctuations and the general consensus is that the roots were causing it.

See ya,
OO

 

[*mistress*]

1/2in nylon rope works well for wick. microfibre towels may have static charge, that may hold onto cations. it also holds LOTS of water. once saturated, maybe tends to hold the water, not so much disperse it...

maybe try this:
bowl of water. pour in kewl aide, or food dye... place 2-3in of frayed end of twisted nylon rope into bowl. observe & note capillary rise of material.

ideally, un-ravel twisted nylon rope into 2-3 strands. place 1 end under transplanted root ball. place other frayed ends in middle of root-stock & walls of container. fill w/ media. leave 2-4in hanging outside of container. the hanging ends touch external res, & draw up water...

supplying water to outside res can be done 1) by top feeding & using run-off as the external res, 2) maintaining external res from another tank.

using run-off from top feeding very simple - it also shows gardener how much water is really required by plant, as it wicks up - or not. can view level. can pour pure water into external res, too... after top-feeding w/ ferts, to trickle run-off...

tan-brown roots, ok... roots groe similar to human fingernails, so oldest part gers thicker. newest parts push thru media/water w/ tip, that keeps shedding, slightly, as it groes...

if use media wick, 100% purlyte/rox works well....

the 'dirty' res, ok, too... if desire more oxygen in it, 1tsp h202 3% every 3-5 days. can siphon that up from bottom res & re-feed, too.

the bugs invade, either/or... h202 can eliminate many, but not all. just keep ph acid (5.0-5.5) & favors plant more than little hopping bugs. spray roots & res w/ dilute h202, every 48-72hrs...

maybe check ph of external res... keep >6.0, ideal 5.0-5.5ph...

hope this helps.

 

[dmoose]

Hi dmoose. I used a microfiber wick on my first ppk run. I found a lot of roots growing into the rez. A media wick may prevent that from happening. Check out my root porn here. I experienced weird ph/ec fluctuations and the general consensus is that the roots were causing it.

See ya,
OO

Thanks! Great info to consider!

1/2in nylon rope works well for wick. microfibre towels may have static charge, that may hold onto cations. it also holds LOTS of water. once saturated, maybe tends to hold the water, not so much disperse it...

maybe try this:
bowl of water. pour in kewl aide, or food dye... place 2-3in of frayed end of twisted nylon rope into bowl. observe & note capillary rise of material.

ideally, un-ravel twisted nylon rope into 2-3 strands. place 1 end under transplanted root ball. place other frayed ends in middle of root-stock & walls of container. fill w/ media. leave 2-4in hanging outside of container. the hanging ends touch external res, & draw up water...

supplying water to outside res can be done 1) by top feeding & using run-off as the external res, 2) maintaining external res from another tank.

using run-off from top feeding very simple - it also shows gardener how much water is really required by plant, as it wicks up - or not. can view level. can pour pure water into external res, too... after top-feeding w/ ferts, to trickle run-off...

tan-brown roots, ok... roots groe similar to human fingernails, so oldest part gers thicker. newest parts push thru media/water w/ tip, that keeps shedding, slightly, as it groes...

if use media wick, 100% purlyte/rox works well....

the 'dirty' res, ok, too... if desire more oxygen in it, 1tsp h202 3% every 3-5 days. can siphon that up from bottom res & re-feed, too.

the bugs invade, either/or... h202 can eliminate many, but not all. just keep ph acid (5.0-5.5) & favors plant more than little hopping bugs. spray roots & res w/ dilute h202, every 48-72hrs...

maybe check ph of external res... keep >6.0, ideal 5.0-5.5ph...

hope this helps.

You can really pack alot of info into a small space, what scares me, is I'm starting to understand!

I tested the MF by putting 1 end into the water about 6 inches below lid, and just hung the other half over the bucket. When I checked on it an hour later, there was a steady drip coming off the MF strip, and every inch of the MF was saturated with water. So I am thinking it is perfect, if not too good, and should be able to dial it in by playing with airgap and/or placement of MF in medium?

My test plant is starting to show signs of life again. It was half dead (hanging limp leaves, otherwise known as "whiskey leaf") when I started from overwater in a shallow Hempy container. It has sat in ph'ed h2o2 h2o, last night I supplemented with GH Flora series. I think the Osmocote+ will release better once under the 1000W HPS from higher heat.

I just finished harvesting the bottom half of my WW in 1/2 Gal Top Fed (1 min on/6 min off) Coco Hempy (recirc - no wick). She provided just over 3 ounces dry. Never showed signs of root bound. I am looking forward to the root autopsy as the root ball is a solid hard mass.

I want to throw a "Thank You" out to all the contributors of this thread! Alot of great stuff in here from which I am benefiting from. I hope to contribute more once I get some ideas out of my head, and into the Garden.

 

[jjfoo]

That's cause I have no idea what it is...

In practice, it is managed by pH... right?

And it's relatively quantifiable?

Keep this in mind...

Plants concentrate minerals. So they can't rely on osmosis or they would lose minerals. They need a way to bring them in.

here is a link to read


http://en.wikipedia.org/wiki/Mineral_uptake


here is somethng from an advertisement for a product that explains a bit of what happens:


"In order for plants to absorb nutrients in the root zone, the nutrients must be dissolved. When nutrients are dissolved, they are in a form called "ions", meaning they have electrical charges. Soil colloids and organic matter have a negative charge, holding the positive charged elements (cations) and minimizing their availability for plant roots.

The most important cations for crop production are potassium (K+), ammonium (NH4+), magnesium (Mg++), calcium (Ca++), zinc (Zn+), manganese (Mn++), iron (Fe++) and copper (Cu+). While Hydrogen (H+) is not a nutrient, this cation plays an important role in the cation exchange equation.

The incremental levels of carbohydrates and carbon dioxide (CO2) created in the more efficient photosynthesis process (above) are exuded from the roots. Plant roots also possess cation exchange capacity. The CO2 combines with water forming carbonic acid, and the H hydrogen ions from the carbonic acid and microorganisms surround the cation nutrients, breaking the electromagnetic bond with the soil. In essence the hydrogen and other proprietary ingredients in TurboCharge are exchanged for the nutrient cations. Once this bond is broken, the nutrients are free to enter the plants roots.

Additionally, the colloidal micelles carry a negative charge on their exterior shell. The root's fibrous hairs are also negatively charged. The addition of these nanometer micelles increases the negative charge in the root zone, attracting/pulling more cation nutrients and water into the root system."

 

[delta9nxs]

I really like the idea of the MF Wick, and seems to to be working pretty good on my test. Can someone explain the benefit of a Media Wick vs. MF Wick? Any observations so far? With the addition of a Top Feed, wether pulse or whatever, how much difference does the type of wick make?

Wicks

The biggest single reason that I use a media wick instead of, or in combination with, a fiber wick is that I don't like stratified media.

That is, anything that layers a medium and causes it to display different moisture properties at different points.

I observed first hand the effects of combining the media and fiber wicks earlier in the beginning of the thread.

And came to the conclusion that my medium was a little too wet. Dead center down low. In the area where a lot of growers in coco reported soggy, anaerobic masses.

In the ppk I have tried to maintain the ability to adjust moisture distribution.

I feel using a fiber wick for long term growing is counter to that philosophy.

I am not saying they don't work. They do work. Mine worked. If I had a container full of synthetic fiber growing material that same material would be in my wick.

I have been looking at all fiber media and when and if I find something suitable the same material will be used throughout the device.

It would be there for uniformity.

I have used a tube for a wick conduit since the beginning here.

I strongly recommend some kind of tube to enclose the wicking material even if that wicking material is just a single piece of microfiber. This tube tends to control evaporation in the “air gap” area and limit root growth into the reservoir.

It also makes the hydraulic properties throughout the whole device more predictable.

About the length of the wick.

The wick needs to be long enough to reach your controlled water level.

And be submersed.

The depth of submersion is not relevant to the operation of a ppk. Enough to operate is enough to operate. The device operates from the waterline up.

You do need to maintain some depth below the waterline to allow for adjustment.

However, any depth beyond this point can function as a reserve if you forget to top your volume tank or go away for longer than expected.

Diameter of wick.

Again, for control of root growth into the reservoir I use the smallest diameter that I can. The 1.5” tube has proven that it is large enough to grow a 20 oz plant.

If you go larger than this you are increasing the size of the perched water table after you have gone through all of this work to eliminate it. That is if you are using a ppk.

The capillary rise potential in this device begins at the surface of the water in your reservoir. Not the bottom of your grow container.

By varying the rise potential, especially with a superconducting fiber, you are creating an artificial floor for that rise potential.

An artificial floor that you may not be able to tune with the range of tools that you have available.

d9

 

[*mistress*]

 

[SCROG McDuck]

Wicks

Thank you, I was floundering here.

 

[jjfoo]

I think this does a good job of explaining how plants uptake nutes via ion exchange and osmosos

http://ezinearticles.com/?Plants-Absorb-Nutrients-by-Several-Diverse-Methods&id=3475506