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passive plant killer
- Thread starter delta9nxs
- Start date
~1/5 volume of container every 2 days... feed-water-feed-water... though, can be feed-feed-water-feed-feed, if maintaining higher ec...
ideally, dont place plant into 4 gal bucket until they 10-18"+, in evry direction... then veg until roots coming out 4 gal (3x3x3'+)... then flower... dont daily water... maybe every other day... only daily if media closest to stem loses moistness...
full strength, gh nutes... input ph 5.8-6.5, depending... on stage of maturity & what nutes wdesired to dominate the solution.
that posted, plants dont drink water in liunear fashion... not daily, nor weekly.
some points during flower they drink more than others & require diff ph & nutes...
this is found more when run same plants over/over... difficult to guage if 1st run... when to maipulate... this/that.
ph of media checked... w/ cheapo soil moisture meter... media @~6.0-6.3, depending... though run-off good to test too... 6.0-6.3... depending... gypsum & other rock-based amends for granular ph adjusting of media - if desired. drenching seems most effective...
only ~30% of media coco, so 60% inert, 10% mineral amendments... they do affect ph, usually raising... use vinegar & lemon juice & molasses & humic acid & potassium silicate & ej bloom for ph up/down/stabilizers... depending on foliar or media drench for which...
this should provide some details of *mistress* wick method... hope post & thread answer q's...
coco+wick+gh flora nova=never dump run-off|pdg’s imaginary/enjoyable garden
delta9nxs uses ppk's...
hope this helps. enjoy your garden!
here is another take on these principles. slightly different but not much.
i probably looked at over 30 different designs before i built mine. all a little bit different.
this particular one looks like it would work ok, but it's not suitable for sustained use with large plants. the cup in the bottom is flimsy at best and i don't believe there is enough res volume.
if i were to grow one of my plants in this i would be watering 2 times a day minimum.
i wanted something that was built for repeated industrial use and could grow large plants.
also, cheap! my materials can be less than 20 bucks a unit.
later, d9
http://sewa-ania.blogspot.com/2009/05/ruminations-on-sub-irrigated-containers.html
i probably looked at over 30 different designs before i built mine. all a little bit different.
this particular one looks like it would work ok, but it's not suitable for sustained use with large plants. the cup in the bottom is flimsy at best and i don't believe there is enough res volume.
if i were to grow one of my plants in this i would be watering 2 times a day minimum.
i wanted something that was built for repeated industrial use and could grow large plants.
also, cheap! my materials can be less than 20 bucks a unit.
later, d9
http://sewa-ania.blogspot.com/2009/05/ruminations-on-sub-irrigated-containers.html
bostrom155
Active member
Wow lots of good reading their D. you did some great research. Nice plants, im after something with nice colas like that.
L
LJB
This is a tremendous thread.
And this is me being sarcastic in response to every last link that delta has posted: "Who needs a scientist to tell them how to grow?"
And this is me being sarcastic in response to every last link that delta has posted: "Who needs a scientist to tell them how to grow?"
L
LJB
plz post the link
bostrom, the colas are not really all that large on the first one, which i'll be cutting tomorrow. i expect the subsequent ones to yield more due to the obvious effects of the slight top watering they have enjoyed.
i have talked about the "moisture" level in the top of the upper container possibly being manipulated to allow the point of equilibrium to be raised inside the pot. thereby exposing more root hairs to nutrient rich fog.
i'm starting to think that the downward plunger effect of the water moving down through the substrate is enhancing o2 in the root zone significantly.
also, it could be flushing the medium slightly with just enough to prevent or slow down salt accumulation.
whatever the reasons, and i'm starting to believe that it is a combination of all these effects, some small amount of top watering produces a better plant. in these 5 gal containers, about a pint a day at lights on seems to work. the rest of the solution, which is now up to a gal day on the largest plants is fed directly into the res and sub-irrigated.
one of the research papers i've looked at recently showed the difference, by computer modeling, in pure drip irrigation and pure sub irrigation. the sub irrigated moisture profile was much fuller, round topped when viewed in profile, and occupied a much greater area of the medium than the pure drip profile, which, when viewed in profile, was more of a downward oriented spike, like a spear point. wide at the surface and tapering to a point further down. apparently the cohesiveness of water for itself causes the column to channel as it descends through the dryer medium.
i think the combination of watering methods creates yet another wetting profile altogether.
when i cut ppk #1 tomorrow i'll de-pot it so we can get a good look at those roots.
i have talked about the "moisture" level in the top of the upper container possibly being manipulated to allow the point of equilibrium to be raised inside the pot. thereby exposing more root hairs to nutrient rich fog.
i'm starting to think that the downward plunger effect of the water moving down through the substrate is enhancing o2 in the root zone significantly.
also, it could be flushing the medium slightly with just enough to prevent or slow down salt accumulation.
whatever the reasons, and i'm starting to believe that it is a combination of all these effects, some small amount of top watering produces a better plant. in these 5 gal containers, about a pint a day at lights on seems to work. the rest of the solution, which is now up to a gal day on the largest plants is fed directly into the res and sub-irrigated.
one of the research papers i've looked at recently showed the difference, by computer modeling, in pure drip irrigation and pure sub irrigation. the sub irrigated moisture profile was much fuller, round topped when viewed in profile, and occupied a much greater area of the medium than the pure drip profile, which, when viewed in profile, was more of a downward oriented spike, like a spear point. wide at the surface and tapering to a point further down. apparently the cohesiveness of water for itself causes the column to channel as it descends through the dryer medium.
i think the combination of watering methods creates yet another wetting profile altogether.
when i cut ppk #1 tomorrow i'll de-pot it so we can get a good look at those roots.
This is a tremendous thread.
And this is me being sarcastic in response to every last link that delta has posted: "Who needs a scientist to tell them how to grow?"
thank you!
i do buddy, i need all the help i can get! when i started growing cannabis indoors, 10 yrs ago, i was looking at two piles, one was shinola, and one was shit, and i didn't know the difference.
bostrom155
Active member
Looking forward to it
L
LJB
I will read this thread in it's entirety again at some point, but not tonight. So the question to is:
Delta, Mistress - you have come to the conclusion that plants prefer bottom feeding?
I think I'm seeing evidence of that in my current no waste coco grow.
Nothing truly scientific here, but it seems the container fills up with water in a much more uniform basis when fed from the bottom and also dries out more quickly and uniformly. This has to do with the raised water table action in the container? How does this occur in a container filled with a uniform substrate?
And the author of the Urban garden blog that Delta linked to is obviously convinced.
Delta, Mistress - you have come to the conclusion that plants prefer bottom feeding?
I think I'm seeing evidence of that in my current no waste coco grow.
Nothing truly scientific here, but it seems the container fills up with water in a much more uniform basis when fed from the bottom and also dries out more quickly and uniformly. This has to do with the raised water table action in the container? How does this occur in a container filled with a uniform substrate?
And the author of the Urban garden blog that Delta linked to is obviously convinced.
Not bottom feeding per se, as ebb and flow is bottom feeding yet retains a perched water table every time it's flooded. A perched water table that can only be eliminated by evaporation or transpiration. It will be eliminated in every case by these forces but it will have a short, damaging life every time you water. Giving rise to the possibility of asphyxiation of roots The same with bottom fed containers with saucer arrangements where you feed the saucer.
Almost all top watered containers also will have a pwt, which also gets eliminated over time by these forces. This will be true even in top watered containers with no bottom on them due to the cohesiveness and adhesiveness of water.
During the life or existence of the pwt the space taken up by the solid water column in the base of the container is depriving the roots of valuable “air” space. Plus raising the odds of roots drowning.
It is the “wick” principle with bottom or top feeding that eliminates the pwt. Well, let me say that technically it does not eliminate the pwt, but rather moves it further down in the container into the reservoir where it cannot interact with the roots. A wick can function several ways. It can be used as a drain only to enhance the evapotranspirational removal of excess water.
see "turftechnow link" this thread, page 5, post 62, for some reason i can't get it to work here. it works there!
the wick can also be used to supply water and nutes to the root zone but if you intend to use it this way you need to design for it right from the beginning.
The air gap between the res and the growing container is essential.
Maintaining as high a water level in the res as possible at all times raises the point of equilibrium in the medium. Increasing the wetted profile.
As you are not letting a pwt exist in the root zone you are providing more o2 overall to the roots. The roots respond to this environment by growing more “air” type roots, further enhancing o2 availability.
“Nothing truly scientific here, but it seems the container fills up with water in a much more uniform basis when fed from the bottom and also dries out more quickly and uniformly. This has to do with the raised water table action in the container? How does this occur in a container filled with a uniform substrate?”
it doesn't fill up with water so much as it fills up with moisture. Moisture with a lot of “air” space. The wetting profile is much fuller with bottom feeding. It eliminates “channeling” where cohesiveness causes the water column to reform as it travels downward.
i am editing to address ljb's questions about how this occurs in a container with a uniform substrate.
the finer the particle size of the substrate, the higher the initial perched water table will be. more particle surface area = more adhesion = taller pwt. the problem being that if you rely on particle size alone to reduce the pwt, as you go up in size you must increase watering frequency to compensate.
Almost all top watered containers also will have a pwt, which also gets eliminated over time by these forces. This will be true even in top watered containers with no bottom on them due to the cohesiveness and adhesiveness of water.
During the life or existence of the pwt the space taken up by the solid water column in the base of the container is depriving the roots of valuable “air” space. Plus raising the odds of roots drowning.
It is the “wick” principle with bottom or top feeding that eliminates the pwt. Well, let me say that technically it does not eliminate the pwt, but rather moves it further down in the container into the reservoir where it cannot interact with the roots. A wick can function several ways. It can be used as a drain only to enhance the evapotranspirational removal of excess water.
see "turftechnow link" this thread, page 5, post 62, for some reason i can't get it to work here. it works there!
the wick can also be used to supply water and nutes to the root zone but if you intend to use it this way you need to design for it right from the beginning.
The air gap between the res and the growing container is essential.
Maintaining as high a water level in the res as possible at all times raises the point of equilibrium in the medium. Increasing the wetted profile.
As you are not letting a pwt exist in the root zone you are providing more o2 overall to the roots. The roots respond to this environment by growing more “air” type roots, further enhancing o2 availability.
“Nothing truly scientific here, but it seems the container fills up with water in a much more uniform basis when fed from the bottom and also dries out more quickly and uniformly. This has to do with the raised water table action in the container? How does this occur in a container filled with a uniform substrate?”
it doesn't fill up with water so much as it fills up with moisture. Moisture with a lot of “air” space. The wetting profile is much fuller with bottom feeding. It eliminates “channeling” where cohesiveness causes the water column to reform as it travels downward.
i am editing to address ljb's questions about how this occurs in a container with a uniform substrate.
the finer the particle size of the substrate, the higher the initial perched water table will be. more particle surface area = more adhesion = taller pwt. the problem being that if you rely on particle size alone to reduce the pwt, as you go up in size you must increase watering frequency to compensate.
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here is ppk #1 on harvest day.
this plant was strictly held to no run off and no top water after the first 2 weeks. the res was topped with adjusted solution to keep ppm's and ph in line.
no ph adjusters were used.
flora nova bloom only in flower and fnb with some cal-nit and epsom in veg. no other additives or treatments.
100% turface.
i got a wet trimmed weight of 856 gr, which at 25% should yield around 7 1/2 oz dry or 214 gr. a small plant for me. the rest of the plants have all had some top watering so we'll see what they produce each week. they are almost all larger plants than this one.
upon examining the root mass i can see that a lot more "air" type roots formed.
i think, after seeing the roots, that if you are using a media wick you don't need a cloth wick at all. i think the cloth wick kept the medium a little wetter than i would have liked.
the first 10 ppk's all have cloth wicks, #'s 11-16 are media wicks only. we'll have to wait about 9 weeks to see the first of those.
this plant was strictly held to no run off and no top water after the first 2 weeks. the res was topped with adjusted solution to keep ppm's and ph in line.
no ph adjusters were used.
flora nova bloom only in flower and fnb with some cal-nit and epsom in veg. no other additives or treatments.
100% turface.
i got a wet trimmed weight of 856 gr, which at 25% should yield around 7 1/2 oz dry or 214 gr. a small plant for me. the rest of the plants have all had some top watering so we'll see what they produce each week. they are almost all larger plants than this one.
upon examining the root mass i can see that a lot more "air" type roots formed.
i think, after seeing the roots, that if you are using a media wick you don't need a cloth wick at all. i think the cloth wick kept the medium a little wetter than i would have liked.
the first 10 ppk's all have cloth wicks, #'s 11-16 are media wicks only. we'll have to wait about 9 weeks to see the first of those.
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Darth Fader
Member
LOL, yes ... that is satifactory! I hope to do as well. What a great experiment though.
Look at those roots!!! Amazing.
Look at those roots!!! Amazing.
they seem to prefer a steady 2-4" of water/solution @ the bottom - thruout the season.
watering the top when becomes slightly dry...
so... can bottom-feed as primary... & top-feed only to maintain slight dampness of top 1/3... they do like the solution to filter thru the media... just not to point where top 1/3 layer is saturated w/ water...
to check ph of external solution wkly. it will climb... as the roots push more atoms into solution via cation exchange... may have to drop ph of input sokution periodically, to keep in 6.0-6.3 range. humic acid seems to do this well.
enjoy your garden!
Darth Fader
Member
they seem to prefer a steady 2-4" of water/solution @ the bottom - thruout the season.
watering the top when becomes slightly dry...
so... can bottom-feed as primary... & top-feed only to maintain slight dampness of top 1/3... they do like the solution to filter thru the media... just not to point where top 1/3 layer is saturated w/ water...
may have to drop ph of input sokution periodically, to keep in 6.0-6.3 range. humic acid seems to do this well.
enjoy your garden!
6.0-6.3 Is this the pH to shoot for in this type of setup?
ph range is generally 5.5-6.5... for healthy plants to assimilate large(r) array of elements.
though, @ certain periods, may adjust to permit this/that elemnt thru more...
w/ gh fnb & tap water, seems to settle ~5.8-6.2, depending on amount (ml) mixed w/ water. even w/ more fnb mixed into water, still seems to settle @ 6.0 or so.
5.8 seems very ideal - in many set-ups... but difficult to maintain if not dumping run-off...
basically, have to add this/that to ph down more, or , use nutes that lower ph...
6.0-6.3 easier to maintain over longer period, w/ humic acid included.
w/ a slightly lower input (5.2-5.8), keep ~6.0-6.2... @ least, w/ water-feed-water, etc...
ph can be lowered by ej bloom, lemon juice, vinegar, or regular ph-down, etc.
hope this helps. enjoy your garden!
though, @ certain periods, may adjust to permit this/that elemnt thru more...
w/ gh fnb & tap water, seems to settle ~5.8-6.2, depending on amount (ml) mixed w/ water. even w/ more fnb mixed into water, still seems to settle @ 6.0 or so.
5.8 seems very ideal - in many set-ups... but difficult to maintain if not dumping run-off...
basically, have to add this/that to ph down more, or , use nutes that lower ph...
6.0-6.3 easier to maintain over longer period, w/ humic acid included.
w/ a slightly lower input (5.2-5.8), keep ~6.0-6.2... @ least, w/ water-feed-water, etc...
ph can be lowered by ej bloom, lemon juice, vinegar, or regular ph-down, etc.
hope this helps. enjoy your garden!
super informative thread, almost hard to read it there's so much info
props for trying something different and succeeding at it. Always room for innovation in my book. That turface stuff looks interesting nice 8 ounce tree there also
anyway, I was wondering if you were to simplify this method for a grower new to passive hydro, what basics would you leave them with?
if running coco/perlite mix or straight coco using the media as the wick, do you just keep the bottom 1" or so of said media in contact with the res/water? I still don't get that part, and assumed that the wick pulled water up, without it how does the plant get it through the hole in the bottom of the 5 gal?
this is why im guessing the roots have to contact the water obviously, but what are the parameters needed to ensure a healthy plant and bountiful harvest? thnx
cheers
props for trying something different and succeeding at it. Always room for innovation in my book. That turface stuff looks interesting nice 8 ounce tree there also
anyway, I was wondering if you were to simplify this method for a grower new to passive hydro, what basics would you leave them with?
if running coco/perlite mix or straight coco using the media as the wick, do you just keep the bottom 1" or so of said media in contact with the res/water? I still don't get that part, and assumed that the wick pulled water up, without it how does the plant get it through the hole in the bottom of the 5 gal?
this is why im guessing the roots have to contact the water obviously, but what are the parameters needed to ensure a healthy plant and bountiful harvest? thnx
cheers
