passive plant killer

[Guest 142956]

Wrong or right I plan only to "pulse" during lights on and I can just as easily do it every two hours. The volume in ounces isn't as important as what effect it gives. Is it a form of rinse or is it helping to draw O2 into the soil or both? I have been fooling with injecting CO2 into solution via a fermentation type of CO2 creation and the solution seems to be absorbing the CO2. Went on an internet Sweet Tooth search, and I love seed searches. I learned that SOL has versions, that Sweet Tooth may be a C99xGrapefruit cross, and that the variety of seeds out there is staggering. I have not decided though Northern Lights x C99 looks very good as does Northernberry. I will also have access to some AK48 x White Widow seeds in a couple of weeks, sounds like a winner maybe.

 

[ImaginaryFriend]

BR,

Is it a form of rinse or is it helping to draw O2 into the soil or both?

D9's bucket design is such that the top third of the container is solid. This is intended to push out stagnant air and draw fresh into the media. I overlooked this tech when I built mine...

The other apparent benefit of the top pulse is keeping salts in solution. Evaporation will tend to increase salts in the upper area of the media. Pulses help keep them in solution, and move them back into the media as a whole...

The volume in ounces isn't as important as what effect it gives.

The volume defines the effect... kinda.

If you pump enough volume to drain back into the lower reservoir, you are moving the ambient salt concentration of the media back into the res. If you pulse enough to keep the salts in solution, but not so much as to 'flush', those salts should stay in the media. The first probably keeps you media 'cleaner' possibly at the expense of your feed solution, while the second methodology probably keeps your solution cleaner, but possibly at the expense of a 'saltier' media.

The former is easier to monitor than the latter.

 

[SCROG McDuck]

I may or may not have any idea about what you are saying. But I'm still going to post. Because... well, I'm going to. Provided media wick is submerged below the surface of the reservoir, all other factors become negligible. The forces related to wicking can be considered to be linear on our scale... that is, there are things pulling directly up and directly down. The addition of curves and bends and additional lengths, one could argue, will slow the wicking effect, but once up and running even this silliness is nearly irrelevant.

Heh, heh, heh... my question.. was a little 'incohearant'..

but you answered it well.. I think.. .. good explanation..

My question is based on how much there will be in the rez, that will never be used because it is below the wick.. 2 gallons in a 3.5 gal bucket... seems a waste, of space. I'd like that to be available to the pant, if necessary.

 

[ImaginaryFriend]

Never used... but still serves as an emergency reserver and a buffer as you remix your bulk reservoirs during auto topoff... There've been a couple of times all the 'extra' nutrients in my res have saved my forgetful ass after the bulk res ran dry.

 

[*mistress*]

in a ppk i strongly recommend against a continuous top feed, especially with coco.

?

constant (continuous, 24/7) top-fed c0c0 works... not simple as han-water @ 1X/day, but works...

fwiw, passive hidroponics has no machines....

...but, if include machines, can run 24/7... whether pulse, or small res that completes volume in 24-48hrs... the concept seem to decrease amount of water used, & maximize nutrient solution efficacy & efficiency.

can be done several manners. simplest, 1. han-water 1x/24, until trickle run-off. stop... 2. continuous flow, 1gal for every 5 gal container. change or finished every 24-36hr... 3.pulse method on second-type tymers...

if gn0 cultivar & water+fert requirements, & prefer... pulse give exact measures... continuous flow w/ small res also give efficiency, w/ no waste, w/ added oxygen from the 'flow'... han-water every 24h give oxygen from evaporation in media, w/ trickle run-off drawn up, if need... 1 & 2 active feed. 3 passive. but if res @ bottom, has active & passive parts...maybe

'pulse' technique for exact amount of fert required, to save on water + nutrients. but same can be done w/ 24/7 feed.

small res, & replace every 24-48hr... very simple. w/ c0c0, rox, perlyte, aquarium gravel, marbles, etc, etc... all work. w/ wicks, or not. activ or passive, or both...

pumps & hoses & tymers, ok... but not needed. 1-3liters/24hr for trees. pour. end...

s.p.faulkner, phd:
what alternative feeding methods are available?
"using the ppm concept, some interesting "no waste" variations of constant feeding have developed. these are designed to minimize the potential for groundwater contamination and are easily adapted to the home garden situation.

"In a method called 'pulse' feeding, the plants are constantly fed with small pulses - tiny doses - of water soluble plant food. research shows that pulsing can be synchronized to roughly match the nutrient uptake rates of the crop being grown. The result is uniform growth and virtually no nutrient loss from the container."

 

[Guest 142956]

Excellent definition of what happens and what the plan actually is. Ok I pulse just enough to keep the soil moist in it total layer, no stratification. What can be done to prevent organic happenings in the reservoir?

 

[jjfoo]

?

constant (continuous, 24/7) top-fed c0c0 works... not simple as han-water @ 1X/day, but works...

I'd like to build a system with two sensors to measure EC and moisture used to supply data to a micro controller that keeps the pots so they stay in controlled ranges. I'd like I would set it to be at the point right before where the perched water table forms.

I would consider the idea that the perfect moisture for the plant might be different than the ideal moisture for the EC to equalize.

maybe there would be wetter and dryer cycles. I'd have the controller log the data and have ability to export it over USB for better analysis.

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? I've been wanting to do this for several months but feel like it would take a large amount of time and I am in the middle of setting up a 4 bucket DWC system to run side by side with a 4 bucket ppk. I'll be starting a thread soon.

 

[jjfoo]

clean

clean

I had to spray for mites several times in flower and would like to not. I use some need nerivitive that is supposedly non toxic to mamals, but I would rather not have mites in the first place.

Do you guys activly battle the mites,too . I've been told be several people that am I hoping for too much to hope to not have them at all.

 

[ImaginaryFriend]

What can be done to prevent organic happenings in the reservoir?

If I understand your question correctly, it seems you are asking how to keep the chemistry of the root zone separate from the chemistry of the lower reservoir.

The answer is the PPK itself. The root zone, buy design is already mostly isolated from the lower reservoir. D9 has observed some roots growing down his wick into solution. I have some slightly different design element in my buckets, and vegged for under a month, instead of two, but currently have no visible roots directly interacting with the feeder reservoir. As I do a shit job monitoring the condition of my res, it is hard to say if my efforts are worth it. From what I can see, though, there is an extremely close correlation as to what I put in there, and what is in there. I would expect more differences due to inverse leaching, but it pretty much works like math for me.

D9 keeps an eye on his, and even with some root penetration, his solutions have shown themselves to be quite stable.

In oldone's last build he had roots growing directly into his reservoir, and still harvested a very nice plant. He's changed his design in this build to a media wick, so his reservoir stability may be the data source for the effects of isolation of root zone.

As there is little mechanical interaction between the majority of the roots and the feeder reservoir, the substantial interaction (as far as I can tell) between the two would require a high-enough-volume-pulse to move the unique organic chemistry of the media into solution, and then flush that directly into the feeder reservoir.

Longwinded answer.

And I haven't even had my coffee.

Just imagine how much worse it could have been...

 

[jjfoo]

From what I can see, though, there is an extremely close correlation as to what I put in there, and what is in there. I would expect more differences due to inverse leaching, but it pretty much works like math for me.

This means the plants are consuming water and salts at the same rate right?

I have found info that contradicts on this idea. I've read that plants take up the water and the salts equally, like if you just sucked some up with a pump or something.

Then I have read stuff that says plants can take up more water than salts (raising the EC of the water more than evaporation alone) or take up less water and more salts (lowering the EC).

I'm a bit confused on this topic. Anyone have any references that deals with this idea?

 

[SCROG McDuck]

This means the plants are consuming water and salts at the same rate right?

I have found info that contradicts on this idea. I've read that plants take up the water and the salts equally, like if you just sucked some up with a pump or something.

Then I have read stuff that says plants can take up more water than salts (raising the EC of the water more than evaporation alone) or take up less water and more salts (lowering the EC).

I'm a bit confused on this topic. Anyone have any references that deals with this idea?

I think you just made it into plant transperaton.
I been trying to figure transperation for a long time..
with too much other stuff to learn, I blow it off..
but this article : http://urbangardenmagazine.com/2010/07/plantworks-part-1-humidity-and-vapor-pressure-deficit/

In Urban Gardener about Humidity and VPD.. is helping me...
if I read it 3-4 more times, it'll sink in...

Hope it helps

I get the : use water EC goes up, ph goes down... most the time.. I'm not patient enough to let it be and see what happens...
so it's ph up, phup, feed (<maybe I have to let/make EC go lower.. ??

And actually, there are a couple other good articles in there if you look around..
Basic and solid gardening information.. doesnt seem to be biased by $$$s but what do I know.

 

[ImaginaryFriend]

It's a gray scale.

It's a gray scale.

Quote:
Originally Posted by ImaginaryFriend View Post
From what I can see, though, there is an extremely close correlation as to what I put in there, and what is in there. I would expect more differences due to inverse leaching, but it pretty much works like math for me.

This means the plants are consuming water and salts at the same rate right?

We should all be very confused.

First, I'll comment on jjfoo's comment on my comment. That my concentrations between my bulk reservoir and feeder reservoir appear to be mathematical (remember, I'm not doing a very good job paying attention) suggests a reasonable isolation between the root zone organic biology and the feeder reservoir. I put some stuff in the bulk, and then when I check the feeder reservoir, it seems to be trending the way I would expect (i.e. becoming more dilute, or becoming more concentrated).

Now, consider the idea of leaching. 'Leaching' (for me) is the tendency of concentrates to move as a result of entering into a mobile solution and moving along with it. In a bottom feed scenario, we are leaching our nute soup up.

Now, consider the idea of equilibrium. Solutes tend to evenly distribute themselves throughout a solution. This has to do with kinetic energy, which (very loosely) is a way of describing electromagnetism, which is a way of describing everything. And I mean EVERYTHING.

Inverted leaching is an idea that should/might apply to pulse-fed/top-watered PPKs. In a bottom fed media, there is a trend to concentrate salts on the top do to the mechanics of evaporation. The pulse/top-water keeps these salts in solution (I fucking hope). If there is no break in the media moisture profile--that is, if it is not wet-dry-wet--that is, all the solution is connected--then theoretically, the solutes should trend towards equilibrium all the way back down the wick into the feed reservoir. I would expect to see, if there were unused salts in the media, a tendency for that to reflect in EC content in the feeder reservoir.

So those are (some of?) the basic mechanics involved in our build out...

Now:

In a media based root zone, we got all kinds of different shit going on...

We treat coco as a hydro media, but depending on the conditions (low EC feeding comes to mind) it will, as a substrate, readily support a microherd. In fact, from what I can tell, it is a great builder for amended organic grows.

Please don't try and pin me down with definitions... what I'm about to type should be read as loose generalizations...

In salt based hydro, we are trying to give the plant everything it needs directly through osmosis at the roots. This is, I think, very generally true in media-less or media reduced hydroponic systems (DWC, rDWC immediately spring to mind).

The other extreem is living organics, where microbiology is encouraged. This complex microbiology develops a physical relationship with roots, and uses its own metabolic process to directly interact with the roots. In turn, the roots directly react with the microbiology by way of exuding sugars, etc. When you read the work of people operating in this sphere, they talk about feeding the soil, and the soil feeding the plants.

These two descriptions are close to the ends of the spectrum.

PPKs with moderate feed rates fall somewhere in between.

Roots are semi-permeable membranes. *mistress* has stated that various roots have various structures that have different permeability profiles. If the root zone immediately around the roots has an active microbiology, this microbiology will define what the membrane has access to.

If it doesn't (i.e. on the media-less hydro model) the nute concentration itself will be the dominant factor in what the plant takes up.

Restating that comment: If there is no microbiological influence, osmotic pressure relative to the nature of the semi-permeable membrane will be the dominant factor in nute uptake.

But this is not black and white.

It's a gray scale.

There is microbiology active to varying degrees in all most all systems (unless someone is running a dead reservoir in their hydro/aero)...

So there is, in almost all systems, something between what we pour over the roots and the stuff that the roots are actually hit with...

Which is why it's not so simple as EC up/down vs. water uptake vs. elephants in the room...

 

[Guest 142956]

If I understand your question correctly, it seems you are asking how to keep the chemistry of the root zone separate from the chemistry of the lower reservoir.

The answer is the PPK itself. The root zone, buy design is already mostly isolated from the lower reservoir. D9 has observed some roots growing down his wick into solution. I have some slightly different design element in my buckets, and vegged for under a month, instead of two, but currently have no visible roots directly interacting with the feeder reservoir. As I do a shit job monitoring the condition of my res, it is hard to say if my efforts are worth it. From what I can see, though, there is an extremely close correlation as to what I put in there, and what is in there. I would expect more differences due to inverse leaching, but it pretty much works like math for me.

Well what I put in the reservoir in my present experiment was Jacks Pro hydro at the 1/2 teaspoon each part and I used Lemon juice concentrate for PH down. My PH stays pretty close to 6.8 and though I put 6 teaspoons in 9gallons of the concentrate in the res. it stayed at 6.8. The experimental res I am playing with has four actual reasons for existance. First is to test the co2 injection into the water which may have allowed some yeast into my reservoir, second to find out what it takes to get PH into a reasonable level and third to find out what goes on in the reservoir without it being aerated. The noted organic activity is a white film on top of the solution. It may not be harmful and as long as it creates no strong odor I'm fine with it. This res is not solidly sealed but no light gets into it. Oh yes, the test is also being run to find out if I can use my tap water with no problems. It appears PH is a problem. Perhaps a better PH down is needed. Perhaps my tap wter is failing the "test".

 

[*mistress*]

 

[ImaginaryFriend]

Oh yes, the test is also being run to find out if I can use my tap water with no problems. It appears PH is a problem. Perhaps a better PH down is needed.

Jacks hydro is designed for use with RO. D9, OO and I have observed pH readings mixing to EC 1.5ish to be around 5.2 +/- when using RO...

I am really curious and mildly confused by your CO2 to the roots thesis. I have always understood an O2 relationship with roots and CO2 related to photosynthesis.

 

[ImaginaryFriend]

For those chasing post 817, it's on page 55. It relates to the hydraulic and osmotic forces related in transpiration. These are also discussed in the URBAN GARDENER link above.

These are good discussions of the mechanical forces involved in transpiration. Keep in mind that the relationship between what is inside the root and what is outside the root is defined by the presence or absence of both media and microbiological elements. That is, if there is a living microherd, they influence the concentrations immediately outside the root's membrane and thereby influence the osmotic and hydraulic pressure distributions.

 

[jjfoo]

I think you just made it into plant transperaton.
I been trying to figure transperation for a long time..
with too much other stuff to learn, I blow it off..
but this article : http://urbangardenmagazine.com/2010/07/plantworks-part-1-humidity-and-vapor-pressure-deficit/

In Urban Gardener about Humidity and VPD.. is helping me...
if I read it 3-4 more times, it'll sink in...

Hope it helps\.

Thanks for the link, I was thinking about stuff like this and it was made clear when they explained it as the ability for air to dry or drying power.

Now I uderstand VPD, but I am trying to understand how water is taken up by the roots. I have read that water gets in the roots by osmosis. This means that if there is higher salt in the plant that they will equalize. I want to know if it does this by the plant losing water or the plant taking in salt without water. Or is it happen simultaneously.

the more I think about it, I'd guess that it is a bit of both, which would mean could change the EC (if you had no evap from the medium)

 

[jjfoo]

If it doesn't (i.e. on the media-less hydro model) the nute concentration itself will be the dominant factor in what the plant takes up.

Thanks for the reply


New question...

Does osmosis through the root have the ability to selectivly uptake specific ions? I'm thinking not. I mean if the plant has a lower salt content than the solution, it takes up all the salts equally, right? Or is ion specifc stuff happening? In other words does the process of osmosis disrupt the NPK balance? Like if for example N has a higher rate on transfer across the semiperiable membrane. If not, it seems like the solution's ratio's of say NPK and stuff shouldn't change. Or maybe I have misunderstood something.

 

[SCROG McDuck]

Thanks for the link, I was thinking about stuff like this and it was made clear when they explained it as the ability for air to dry or drying power.

Now I uderstand VPD, but I am trying to understand how water is taken up by the roots. I have read that water gets in the roots by osmosis. This means that if there is higher salt in the plant that they will equalize. I want to know if it does this by the plant losing water or the plant taking in salt without water. Or is it happen simultaneously.

the more I think about it, I'd guess that it is a bit of both, which would mean could change the EC (if you had no evap from the medium)

VPD allows transport to the plant... sucking H2O, O2 & salts up, thru roots,
into plant for photosynthesis (<Phonetic spelling<phanetic < pathetic, spelling, too! LOL!).

I thought it goes: vpd (humidity&temps)=transpiration rate: TR=intake of salt & water.
Maybe I still dont get it.

 

[ImaginaryFriend]

Does osmosis through the root have the ability to selectivly uptake specific ions? I'm thinking not.

*mistress* once noted that there are different root structures that are optimized for different nutrients. This implies a different permeable membrane in different root structures. This implies the possibility of certain roots selectively taking up certain ions. But within this context, my brain agrees with you, that is, insofar as we are not dealing with bio-involvement, the balance on both sides of the root membrane will be defined by osmotic forces.

I mean if the plant has a lower salt content than the solution, it takes up all the salts equally, right?

Are certain membrane is more easily permeated by a certain molecular structure than another? I do not know the answer to this, but it seems possible that this is the case. If this is the case, than you could have an unbalanced ion uptake.

In other words does the process of osmosis disrupt the NPK balance?

If we had a perfectly balanced NPK (and all the other micros and macros) profile that matched our environment and genetic and phase of growth, I can see a perfectly balanced uptake. The necessity of changing out reservoirs is based on the fact that we do not. The Lucas formula is a very imperfect, but very buffered nute program that self-buffers its addbacks, but is (from what I've read) hardly a perfectly balanced nute regime. The fatman has suggested that the most significant uptakes are with lower cal concentrations, but in the absence of that buffer, things can get squirrely fast.

It should be noted that I don't really understand the biochemistry of 'buffers' (or a lot of other shit that I blithely write about).

pH plays a role in nutrient availability. As certain nutes are absorbed from the solution, the pH changes. So it changes nute availability.

How many times have you read someone in root submersed hydro say, "right after I change out my nutes, I get a surge in growth for three or four days," like it's a good thing rather than an indication that their solution is out of whack for the last 11 days they're leaving it in there...

Like if for example N has a higher rate on transfer across the semipermeable membrane. If not, it seems like the solution's ratio's of say NPK and stuff shouldn't change. Or maybe I have misunderstood something.

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