Aquaponics in soil

[Elan yadan]

What would be a good way to filter the runoff and keep it soil-free. Someone suggested a particle filter. Or draining into a bed of hydro. Perhaps putting rocks in the sump tank. Any thoughts please. Thanks

[Jon Parr]

Why exactly do think the "extra nutrients" will lower pH? I assume you're wanting to use hydro nutes? And by "stimulants" do you mean some potassium rich "bud blaster" or something? Or an organic boost like bat guano? Just curious. Most nutes require pH balanced (or manipulated) water before mixing. Fish are actually more tolerant of low pH than bacteria, which die at 5.5, so keep above that mark. Oyster shells are very slow to change pH, and it isn't practical to alter it up and down in a recirculating system.

[Elan yadan]

Yes was planning on using pk boosters but not bat guano. Was hoping to use my turtles to get the benefits of bat gauno organically. So I need to consider what feeding schedule (plants:meat) I should have them on. Does meat feed produce more nitrogen and plants more PK or reverse? Questions..

[Elan yadan]

And did my removable standpipe make sense? I may have worded it a bit confusingly. There would be a connecter piece at the base of the tank w an ez release fitting underneath to easily remove the standpipe. Then that would connect to an elbow and then a valve en route to the soil bed. If i close the valve then I could remove the standpipe w/o water being sucked in. As I slowly open the valve the waste at the floor of the FT would get sucked in. Once the rock formation is clear of waste, close the valve, put the standpipe back in, lock the ez release fitting, add my boosters into the standpipe and let the tank fill. Once a week heavy feeding. What do u think?

[Vlad Jovanovic]

Hi Elan, thanks for the friend request, and since you asked what I thought...Honestly, (for a whole bunch of reasons), I would avoid the soil altogether.

1) Soil (even bagged and bought) can seriously impact the bio-security of your system (as some who are using soil to sprout seedlings with have/are finding out).

2) It would take a considerable amount of attention to filter out the soil...needlessly complicating things adding fail points as well as additional equipment and maintenance that is otherwise unnecessary.

3) Soil (now this depends on the type of soil to a degree but still...) tends to compact and has a horrible air to water ratio in a system that needs re-circulate as often as an AP system would. This is GREAT for pathogens, but not so hot for plants. (Again, this can somewhat be worked around. But would in and of itself constitute one or more more "pain in the ass" element(s).

4) You would then have no way of filtering out the run-off from your "nutrient additions" (what ever they may be) and depending on what you had in mind, could be very bad for your system (algae blooms, O2 depletion, pH swings etc)...

5) Did I mention that it's totally and utterly unnecessarily complicated? 

I'm gonna go and re-read in detail what's been written in case I'm not understanding something. But, can I ask you...what were your original reasons for wanting to use soil? If we knew why you were wanting to do what you want to do it might help in better answering some of these things in a way that isn't so negative (by negative I mean answers like "don't do it")...

Answers like mine, thus far, probably don't help you in as much as you are dead set on using soil for some reason. So knowing why (or even if) you are dead set on it might help us to help you...

[Jon Parr]

I've got a feeling that Elan is happy with the dutch growing style of placing pots on a lined floor, and flooding the floor with water every so often, and allowing it to dry in between. I have done this style with good results using AP water, though not recirculating. Here is another case were soil/wicking combo could be used, though FT contamination is certainly something to consider. 

Some good diagrams here, BTW, http://www.dbcourt.co.uk/hydroponics/System%20_types.html#Aeroponic...

I've had luck with simply placing some plants in pots on an NFT trough, and in fact have some peas growing that way right now.

[Elan yadan]

Vlad thanks for reply. Well.. First I already have over 50 bags of fox farm soil mixed w perlite, some hydroton for aeration and pro mix and I would hate to have to replace it! And second, I've been shooting ideas back and forth with Aptus tech support and obviously adding nutrients into an AP system would be bad for the fish. He suggested soil as the salt buildup wouldn't become an issue.

So I'm considering draining my soil bed into a hydro bed and using the hydro bed to filter the runoff. Since the soil only needs watering once every 2-3 days that would give me plenty of time to recirculate the runoff from the sump tank to the hydro bed many times before it gets pumped back to the fish. I could cycle the hydro bed every 2 hours or so? Just getting creative here trying to find a way to grow in soil and AP together so I can get my boosters in there as needed. Where there's a will there's a way?

[Elan yadan]

Also I should add. Was thinking an inch of sand at the bottom of the soil bed would catch a lot of the sediments too. Already got a filter to catch the last of the particles. Shouldn't be too much of a chore keeping it clean. It looks like a garden hose attachment piece. Very simple filter. I'm using flood tables that can only hold 4-5 inches of water. Using 5 gallon smart pots I'm hoping 3-3.5" of water should be enough for the soil to swell up and give the roots what they need to thrive and also would leave the top layer nice and dry. The other thing to consider is that the soil will retain a lot of the water so more water will have to be added regularly. Tech support also suggested that tap water filtered from chlorine should work fine which is great to hear. That would save me some money on Ca/Mg and the hassle of using RO water. I could draw a line in the sump tank and once the level gets low, simply use a garden hose w a chlorine filter on it and water the hydro bed until the sump tank reaches the desired level. The entire system will be gravity based w the FT at the highest point draining to soil bed, draining to the hydro bed, draining to the sump tank. Two pumps in the sump. What do u think?

[Elan yadan]

A 4x4' flood table holds 16- 5 gallon smart pots nice and snug. I could fill in the gaps between the pots w hydroton. I'm not planning on hitting the plants w aggressive levels of boosters. Just enough to keep the plants and fish happy. Not sure if you heard of Aptus but they encourage growers to use whatever base they are comfortable with. I would feel very comfortable if my base came from my fish and turtles. Perhaps I could control their NPK production thru feed? Plants:meat depending on veg/bloom stage? What produces more NPK. My fish and turtles eat plants and meat! Lol

They also make base pellets that I could use while the system is in the early stages of cycling. Could a worm/bacteria colony thrive in soil? I'm keeping my fingers crossed!

[Vlad Jovanovic]

@Jon...Ahhh, the old... ehem...heirloom tomato set up...

@Elan, it's not necessarily that adding any and all nutes will harm the fish. I've been coming up with ways to do that that are beneficial for the fish (when possible) but it requires mixing up certain and very specific reagents and might not be possible if you are using complete "store bought" hydro formulations...anyways...

Will your cultivars be 'heavy feeders?

If you're using smart pots, you could employ the method I described in the dual root zone thread Jon linked. that should help keep excess nutes out of your AP water...

Yeah, I'm a firm believer in working with your tap water. Depending on it's composition it can be a decent source of certain nutrients in and of itself. (A simple kH/gH test kit should give you an idea of what you can expect...but it sounds like youve already got that covered...Your probably already aware that when you drop your tap waters pH with say HCL the CaCO3 dissociates into plant usable Ca2+ and some CO2 blablabla...same with magnesium carbonates in the source water etc...I think learning to use those type of things to your advantage is much more thrifty than using RO water, then having to replenish all those minerals...so kudos on that one.

What's the "soil bed" set up like? Could you describe it? And the "hydro bed"? Sounds pretty cool. And definitely different than your 'run-of-the-mill' AP set up. Man, you just gotta love this stuff. There are so many ways to make it work as long as you respect some core principles/chemistry...Sounds like you've given this some considerable thought, it'll be cool to see how it works out.  

Also, I'd highly suggest cycling up with humonia. It will put your system at an immediate nutrient advantage (as opposed to using janitorial ammonia) without compromising fish health or any solids...

Jon Parr said:

I've got a feeling that Elan is happy with the dutch growing style of placing pots on a lined floor, and flooding the floor with water every so often, and allowing it to dry in between. I have done this style with good results using AP water, though not recirculating. Here is another case were soil/wicking combo could be used, though FT contamination is certainly something to consider. 

Some good diagrams here, BTW, http://www.dbcourt.co.uk/hydroponics/System%20_types.html#Aeroponic...

I've had luck with simply placing some plants in pots on an NFT trough, and in fact have some peas growing that way right now.

[Vlad Jovanovic]

Sorry Elan, I didn't see your last post there...well the NPK value of your effluent is going to be determined by first, by your input feed, and that species digestive system and the way it assimilates those elements and transforms them into mass. My suggestion would be to buy the highest quality feed that you can afford (like Sketting USA...they used to be called SilverCup) Fish have a hard time digesting certain types of plant proteins and gluten that comes from grain...so don't cheap out and feed them dog food or some such silly thing...yes, people have done that...also a good feed will have less "ash" content and can really cut down on the amount of solids that your system will have to deal with.

Turtles I don't know about, but P should not really ever be a problem with fish (depending on stocking density and feed). N should also obviously not be a problem.

 K often seems in short supply (particularly in new-ish AP systems), but humonia cycling and/or a simple fish beneficial KCL addition, timed and dosed properly should take care of that. Mg as well...but is/can also be safely and inexpensively added in a number of ways...so no problems there... Yeah, there are many ways to safely and naturally and inexpensively skin this cat without resorting to nutes derived from the petro-chemical industry...

this may be of some interest to you...   

http://rho.uesc.br/cursos/pos_graduacao/mestrado/animal/bibliografi...

Just to give you a baseline ball-park starting point of what you might be dealing with. (Keep in mind the 'exactness' of the numbers applies to that particular species of fish, fed with that particular feed...which isn't even a "top of the line" feed or anything special)...

[Elan yadan]

Yes heavy feeders. I considered filling the bottom of the pot w hydro and putting the soil on top but the soil can only be watered every 2-3 days and would need deeper grow beds, right now I'm using small grow beds. Also it would be a messy job keeping the hydro free of soil after each harvest. You may be surprised to hear that I am new to gardening lol. Yes I love this stuff too it's fascinating. It's the future. Also that stuff u were saying about the water might as well have been written in another language LOL I didn't recognize any of it. But I will take your word for it. I'll look into having the tap water tested. It's los Angeles. Must be filthy?

Ok.. Here it is. So I have two turtles, two goldfish and 3 algae suckers. They're 4 yrs old and make a mess. I need to put this family of happy friends to good use. So I drew up this system design. A 3x3' fish tank 18" height half-full. Standpipe at 9" height. I have a rock formation w a hollow center for a filter that I removed. Holes on the bottom of the rock piece. Two air/circulation pumps. The water manages to stay waste free w it all collecting inside this rock formation. So I figure if I put the standpipe thru the bottom center of this rock piece then the dirtier of the water will flow in first. Also, if I make this standpipe removable at the base of the FT and control the drain w a valve then say once a week, I could remove the standpipe and flush the heavier solids that collects at the base right into the drain like a heavy weekly feeding.

I'll need to consider using plants in the hydro bed that will benefit from this runoff. I was hoping to grow wheat grass catnip lettuce and tomatoes peppers maybe strawberries but I'm concerned if the nutrient boosts will hurt these plants. Jon recommended cucumbers. What do u think?

I'm curious about what you recommended for cycling the system too. I've never done this before. I'll definitely have some questions about that. Thanks btw. And Jon too. Appreciate the info.

[Elan yadan]

Great. Thanks! I'll read this article. I was considering using red worms in the soil and feeding them to the fish and turtles. They also eat lettuce and fruits. Pear peach strawberries. Even the fish nibble on the fruits lol. I was thinkng I could get the benefits of bat guano from my turtles. How mch different can their waste be? Depending on feed I suppose..