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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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A couple of days ago I noticed a pod forming on one of the dual root zone plants. Today there are a 'bunch' more. Here are some pics.... Yippee! The canopy is also filling out really nicely (to put it lightly).

Also, the pepper plant that was 'saved' from pythium death in the other system has form pods as well. I am a happy camper today. 

 

Just another pic update. Many, many little (and a few not so little) peppers...This little 'Dual Root-Zone' idea has exceeded my expectations thus far, and I'll definitely be using this technique in a real AP setting with even more nute hungry tomatoes and such...

  

Wait, just noticed this. What nutrients do you use and from what source, pee ponics, worm castings, salts? 

All of the above is the short answer. Salts in the form of Potassium BiCarb foliar and chelated iron. Started out with just water and iron in the reservoir, (plant usable calcium is released from hard water when you use acid to lower the pH and there is other stuff in groundwater as well.

I did not have my water lab tested, so I do not have a baseline reading). Then went to that same water and pee and worm tea in a sock, brewing in the reservoir itself and a couple bags onion bags of hydroton in there, with all kinds of blood, bone, ashes (or pH adjusted lye water), TE's and such being fed into the top portion...

Then back to just water (and whatever is in it) and iron in the reservoir, a week or two into flowering... with mostly K both foliar fed and in the upper portion of the net pot. I was worried about P and K but I think I'm probably over doing it? The bone powder is probably even more slower acting than I thought. And there are a gazillion flowers and pods. I've grown quite a bit of these from seed, both in the ground and in regular pots with a home-made potting soil recipe (side by side to compare zeolite vs no zeolite)

and have never seen them like this. I'm pretty stoked. These peppers seem to grow by the hour and there are so many of them ...

And i didn't "train" them into just two main fruiting branches like I often do, some of the earlier 'sucker's are as thick as the main branches. The sucker's, sucker's sucker's have sucker's...and are all producing. But I had to thin many out mostly from the middles or where the two plants run into each other (for some ventilation) and where the one blocks too much light IMO for the Hab(s).

The Habs are much, much slower, even they have begun to form a few pods (very tiny pods, and don't make as much progress over a given period as these peppers do). Also there have been some weird deficiencies on the Hab's at times that don't show up on the others?

Eric, I just tried to take a pic from the same perspective as 4 days ago, but I've pruned some leaves since then so some of the 'framing markers' aren't there...

 Here's an other one. Pretty decent growth when compared to the pics from about 3 weeks ago...(It's kinda hard to gauge their size from pics though).

Hmm...I'll have to try this someday. (ecstatic emotocon)

Vlad Jovanovic said:

All of the above is the short answer. Salts in the form of Potassium BiCarb foliar and chelated iron. Started out with just water and iron in the reservoir, (plant usable calcium is released from hard water when you use acid to lower the pH and there is other stuff in groundwater as well.

I did not have my water lab tested, so I do not have a baseline reading). Then went to that same water and pee and worm tea in a sock, brewing in the reservoir itself and a couple bags onion bags of hydroton in there, with all kinds of blood, bone, ashes (or pH adjusted lye water), TE's and such being fed into the top portion...

Then back to just water (and whatever is in it) and iron in the reservoir, a week or two into flowering... with mostly K both foliar fed and in the upper portion of the net pot. I was worried about P and K but I think I'm probably over doing it? The bone powder is probably even more slower acting than I thought. And there are a gazillion flowers and pods. I've grown quite a bit of these from seed, both in the ground and in regular pots with a home-made potting soil recipe (side by side to compare zeolite vs no zeolite)

and have never seen them like this. I'm pretty stoked. These peppers seem to grow by the hour and there are so many of them ...

And i didn't "train" them into just two main fruiting branches like I often do, some of the earlier 'sucker's are as thick as the main branches. The sucker's, sucker's sucker's have sucker's...and are all producing. But I had to thin many out mostly from the middles or where the two plants run into each other (for some ventilation) and where the one blocks too much light IMO for the Hab(s).

Pic update...snapped yesterday. I've had to resort to heavy pruning as it was getting just too unruly...not much else new, things are ticking along nicely. The Habs also have 'many' small fruit, but are still mostly just flowering. So I'm since with this system I am able to, I am now catering to the specific needs of each cultivar in regards to where they are in their development. K heavy  for the guys pictured vs. P heavy for the Habs...

 

I've never grown peppers, but now I want to!

Another update...pics from yesterday. The ones I haven't eaten already are ripening well. The Hab's are puttering along slowly but surely... 

Would this type of net pot "setup" work in AP gravel grow bed that is on a flood and drain with bell siphons?  If so how much iron chelate, worm tea and the blood, bones and ashes mixutre would you put in a 1200 gallon total system ( 2 - 375 gallon fish tanks 5 - 100 gallon GB's and 4 connected sumptanks the GB's drain that total around 500 gallons total)  Also where would you reccommend to put the sock with the "tea" mixture in it in the system. The fish tank or sump tank?  Also whe you say the blood,bones and ashes mixture what are you using and how much of it do you use.  Thanks so much :)

Vlad. Curious what your conclusion to this experiment was. Where you able to measure any contamination levels in the reservoir? How was your root development in each zone longer term, specifically the "water" zone? 

If doing this with something larger (tomatoes) and applying to an AP system, were you thinking a dual zone net pots which were only half buried in a flood/drain media bed or something like a constant height, post media bed DWC/trough?

Hi Brandon, yeah this experiment was done for just such a gravel grow bed in mind (since I have 8 of them only timed flood)...your 'net pots' would be a buckets (size depending on what you were growing) say 3 to 5 gallons with a bunch of 1/4" holes drilled out the bottom. The bucket is where the mixture would go...kinda just like growing potted plants, only with gravel at the bottom of the bucket. Place the bottom of the bucket just below your media beds water line. I wouldn't bother burying it too deep as it seems like pointless work, but you can.

The iron chelate can still go into your AP water as usual. Or if/when you water your buckets you can dose that way as well. The worm tea was used in lieu of fish, so you shouldn't really need that if your system is proportioned and/or stocked correctly...but you can still use it in either sump or tank next to wherever you have an air-stones.  

It doesn't seem to matter a whole lot what/how much you use in the 'absorbent' layer...especially if you have plenty of worm castings in there. A small hand full of hardwood ashes and bone-meal should be fine for starters. You can either top-dress or add nutrients (organic or otherwise) in solution later if/when you need to. Remember the point is to keep all those things from entering the system water.

I'd forgo the blood-meal though, it is a wonderful source of N, but you wont need that at all if you have fish. The castings should provide plenty by the time the roots make it to the AP system water...



Brandon nardoianni said:

Would this type of net pot "setup" work in AP gravel grow bed that is on a flood and drain with bell siphons?  If so how much iron chelate, worm tea and the blood, bones and ashes mixutre would you put in a 1200 gallon total system ( 2 - 375 gallon fish tanks 5 - 100 gallon GB's and 4 connected sumptanks the GB's drain that total around 500 gallons total)  Also where would you reccommend to put the sock with the "tea" mixture in it in the system. The fish tank or sump tank?  Also whe you say the blood,bones and ashes mixture what are you using and how much of it do you use.  Thanks so much

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