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Here is an idea that I believe if done PROPERLY could be used in an AP system with fish…[edit* as of this writing, it has been used in dozens of systems with fish]. I first described what I've done in Wil’s ‘Medicinal Plants Any Luck’ discussion (there is some encouraging feedback from people I respect there, and other ideas we bounced around which might be worth checking out)…

 

The deal here was that once my AP system is up and running, I wanted be able to cater to the needs of specific plants that may have nutritional requirements that a brand new system might not be able to provide (so called ‘heavy feeders' like tomatoes, corn, cucumbers, for instance). Patience, I've been told, is not one of my strong suits. And I don't want big huge tomato plants with no tomatoes, or even no flowers, stuck in a nitrate induced perpetual vegetative twilight-zone of just green leafy growth. Yet  pouring different nutrients, or nutrient products into your AP system (like P-K, “bloom/flower” type products) may not be advisable for a number of reasons discussed at length elsewhere. So what I did was the following…

 

Research shows that plants in nature tend to specialize the function of their roots. To make a long story short, we’ll divide the rhizosphere into two categories: upper roots, and lower roots. The upper roots tend to spread throughout the top soil specializing in seeking and up-taking nutrients, while the lower roots go downward seeking out moisture, specializing in water up-take. Using this concept I’ve taken five 13cm net pots (for hot peppers, but you can go larger for tom’s etc…) and set them up in the following way...

 

Fill the bottom half of the net pot with hydroton (rinsed, presoaked). Put a thin layer (5-10mm thick) of rockwool on top of the hydroton. (I have a rockwool cube and a sharp ceramic knife, so this was easy, but you can tear of pieces with your fingers as well). The whole purpose for the rockwool is to act as a barrier between the upper and lower zone of your net pot, so make sure all the hydroton is covered.

Fill the remainder of the net-pot with a mixture 13/perlite, 1/3 vermiculite, 1/3 cocco coir. To this mixture I added about 10% worm castings a handful of hydroton, to help with compaction, and about 5% Zeolite (I might forgo the Zeolite in an AP set-up though).

Then I poured water into this top portion and noted when water started leaking down into the hydroton. This way you will know what the absorption capacity of the upper layer is. Later when feeding your plants use slightly less than this ultimate holding capacity amount. Three small weekly feedings is probably better than one large one. This is an extra pot that I took a picture of...

If you had some screen material you could line the inside wall with it, but probably not necessary.

I planted my 3 Habeneros and 2 Hungarian Wax into the net pots. They have been placed into an aerated DWC bin. The reservoir holds only water (no nutes) and the roots have begun to dangle in it. There is about a 1" air-space between where the rockwool layer is and the top of the water, so that the upper layer doen't get too moist from over-wicking. This air space might also help with oxygenation of some of the roots.

Every third day or so I feed a solution of liquid home made nutes (but you could use whatever type you wanted, orgaic hydro store bought, mineral salts etc)…I pour only enough solution as the top mixture will hold so as not to contaminate the reservoir (or an AP system) with nutrients. They are growing like mad thus far.

 In an AP setting the bottom roots would be exposed to both moisture and mostly nitrates, while the upper to whatever you wanted (though I imagine and K, Mg and P...would be among the prime candidates...and perhaps P if your system is real, real new.but P shouldn't ever really be a problem in a well fed AP system).

As long as you didn't over saturate with your solution while top feeding your plants, you should be able to keep any nutrient contaminants out of your AP system. Another benefit, would be less root mass to deal with in your grow bed (which is where this idea evolved from anyways).... I had originally planned on using 'huge' net-pot-bucket-with-drilled-out-holes filled with hydroton to help contain some of the root mass of the tomato plants, and make it easier too get it out of the grow bed when the time came. Reclaiming and re-using the hydroton would also be simple. Since I am relying on my 8 IBC media beds to pre-filter the DWC troughs, the last thing I need is a root bound anaerobic bed to deal with because of a couple of tomato plants. This method can address both the nutrient issue, and may help keep the more monstrous roots contained and more manageable. (Less maintenance to the grow bed).

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Ok, so we all know cucumbers grow really fast, and so, are absolute nutrient HOGS, especially in the K and Mg department. We've harvested a little over 20lbs in the 3 or so weeks since putting the 8 plants in the system. I read this study a while back http://www.plant-dynamics.nl/UserFiles/File/pdf/Scientia-komkommer.pdf

and decided to see for myself...Sure enough, on the plants where I did not thin the early first setting fruit (6 to 9 fruits on the primary stem), the fruit further up the stem aborted...Whereas on the plants that I thinned out fruit, keeping only 3 to 4 of the first to set, subsequent fruit developed and has kept on developing just fine...Except for this one super beast of a plant... it just appears to be particularly vigorous and doesn't seem to give a goddamn that it's overloaded with fruit. Somehow it's able to transport all the needed nutrients along it's entire length as well as it's primary (and for now secondary) laterals... definitely the Austrian Death Machine of the bunch...

  

  This second pic is the pot that had the struvite that I made and zeolite mixed in, it seems to be doing among the best (though none of them are doing poorly :)  Might just be a coincidence, but either way...I'll take it...

Well, a number of the cucumber plants have reached the top wire which is a little over 11 feet from the grow beds, so I need to set up another string(s) to lead them somewhere...The shortest vine is now 10 feet, while the longest are about 13 feet. We've harvested just under 120lbs off of these 8 plants so far. (I planted them in the system on April 20th)...

I've pruned all the fruit and laterals from the bottom 2 feet of the plants and from here on out will basically be pruning to the tune of what A. Papadopoulos described in the book that I linked earlier.

  The dual root zone toms are doing well too.

 

These aren't really showing any signs of stopping. 

On some of the plants, I've pinched out the growing point to try and stimulate secondary fruit back down on the main stem at the leaf axis of the new laterals...

I'm pretty glad that I didn't go crazy thinning out much fruit, as I would have totally short changed myself. Apparently this cultivar, using these methods, in this weather, can take the heavy load.

Part of the reason I wanted to grow these was because of the many earlier reports that cucumbers in AP don't do well at all. That seemed like a bummer because to me cukes seemed like a great choice for an AP greenhouse...Everyone gets so hung up on tomatoes for some reason, but a tomato grown in a watery environment tends to taste...well, pretty watery. Cucumbers however, grown in a watery environment taste absolutely fabulous! Tomatoes are not known to like very high relative humidity, like you would tend to have in an AP greenhouse, cucumbers however thrive in high relative humidity environments. It seems that as long as you take care of a few special considerations, they do just fine. We're at well over 145lbs of cucumbers (and still going) and that's off of 8 plants 

This has been fun.
 

Ok since I'll be away from the farm for a while, I took down the DRZ cucumber set up early, even though it was still producing. The plants were definitely showing signs of fatigue though. 205lbs of edible cucumber from these 8 plants was the final count. 

 Some of the water roots...

The upper soil-less layer was filled with very fine thread-like roots. And pictured below is what the bottom (hydroton portion) of the bucket looked like when I flipped out the contents...These are now in the compost pile instead of helping to clog up the grow bed.

Ok, time to try out some of the worlds hottest peppers in this set up...

In sets of two each...

Naga Morich

Chocolate Bhut Jolokia

7 Pod Brain Strain

and last but certainly not least, the now famous Trinidad Red Scorpion (of which the Butch T variant had the honor of being the world's spiciest pepper clocking in at a whopping 1,463,700 Scoville heat units in March of 2011 The current record holder is a variant of the same pepper, being called the Trinidad Moruga Scorpion). 'Salsa nite' around here should be fun this year, hehe...(BIG thanks to Jeffrey Ihara!)

Hello Vlad... these "fabric" pots that I see you experimenting with... would a #5 (as seen here http://rootpouch.com/prices) do the job for tomatoes, cucumbers. watermelon, peppers, etc...? Are you happy with the way they performed vs the plastic pots? I am sure it helped avoid algae too.

Would I be correct in assuming you put holes in the bottom of these (perhaps the sides too at the bottom?) so they allow the water seeking roots to get out into the media bed?

How far below the soil line does water come to? I assume the hydroton within the pot wicks the water up to the soil layer.

I am looking to switch completely to this way of growing... have you gone the route of using it within a closed loop AP system or are you running this "fishless" still and using water from an AP system?

Sorry for all the questions... I am just so intrigued by this method of growing after having spent 2 1/2 years battling with regular vanila AP and all the shortcomings. Is there anywhere else I can read up more on what you're doing with this method of growing? Have you found an ideal mix for the soil layer?

Many thanks for sharing all you have in this thread, love seeing this "hybrid" side of things, bringing the soil part back into it all.

Shaun

Hi Shaun, the #5 pots you linked are 16 liter pots, which is about twice the volume as mine...which is great. Part of the whole 'charm' of these black 'smart pots' is in that the fabric is of a type that will prune the roots that come into contact with it, I don't know if the same is true for the 'rootpouch' pots.

No, I did not put any holes in them anywhere, only in the white plastic ones (shown best on page 3). I believe I used a 5mm drill bit.

The water line is about 2 or 3 inches below the soilless media mix.

These are in an AP system with fish.

Nope, Sylvia's site is about the only open forum that I participate in. (I've not been home for about 3 months, so this time around there are no weekly updates with pics and all...Now that I'm here, I'll try to do a small write up with pictures before this weekend is over ).

Yes, I've long ago settled on an "ideal" mix for these sorts of things...It's pretty much laid out in the OP...except that I've since decided to forgo the coco coir and have gone back to using 1/3rd sphagnum peat instead. I feel the sphagnum peat just has a superior structure for horticultural purposes and does not come with possible salinity issues as coco coir sometimes does. 

Alright, so I've not been home in almost three months. This is what awaited me in the DRZ when I when I arrived. 

 The next pic (below) is the veil of branches that overflowed beyond the edge of the grow bed...

 And if we peel back the curtain and take a peek at what's behind the green...

 I'm pretty happy with the results. These are among the world's hottest chili peppers, and folks often complain that they don't produce very many pods, so once again, I'm stoked and thankful they did so well. While I was gone, my wife fed the fish, and followed a relatively simple instruction set to amend the upper portion of the DRZ with some organic nutrients and the special microbial brew myself and a few PhD rocket scientists (actually neither are not rocket scientists, but microbiologists renown in their particular field) have been working on.

I'm thinking that one more of the benefits to this method is that I can prune back, remove and overwinter these plants quite easily now and just plop them back in the grow bed come springtime giving them (and me) a grand head start on the new growing season.

Awesome stuff Vlad!

In reference to the previous post "I've since decided to forgo the coco coir and have gone back to using 1/3rd sphagnum peat instead"... is the s peat not more likely to carry baddies, such as pythium? Just curious as it seems there have been issues with both and most end up with a preference for coco coir.

So from you OP, you prefer "a mixture 1/3 perlite, 1/3 vermiculite, 1/3 cocco coir + 10% worm castings a handful of hydroton".... curious on this choice vs a good soil mix, assuming one was making ones own soil vs buying stuff you would have no idea what was in it? Is it simply easier to manage or are there other reasons, such as soil diseases?

OK, great, so it is about the disease side, better to start with a sterile environment and then inoculate with all the good guys.

I referenced this product - http://www.fungi.com/product-detail/product/mycogrow-soluble-1-lb.html 

From this mix however, what are the crucial good guys one should have?

All those guys are good to have. Two things though at first come to mind:

1. Bacteria stored in a dry carrier traditionally has some major shortcomings (this is not the case with fungal spores though, just the bacterial portion), so more recently liquid carriers and methods have been developed which resolve some of these issues surrounding effectiveness.

2. They, it would at least appear, took the old "the more the merrier" strategy throwing in just about every beneficial bacteria that has as of late made the gardening scene in any capacity...which is fine, just probably not very effective.

I've given some thought to the nitrate problem we spoke about. There does exist a way that is very cheap and does not require any extra space or equipment. However, if not done properly, it could get ugly. It would require that you understand what you are doing, and that you are precise as well as diligent about it on a daily basis (which I'm sure you are capable of).

I'll e-mail you a link(s) to get you started and you can decide if it is something worth pursuing.

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