Backyard Aquaponics
A place to discuss aquaponics

I've been growing tilapia for 6 months now, and now its time to build a "real" system. So this will follow the creation/evolution of the design and construction. But first, how NOT to do aquaponics. The first pic shows my fish tank on the left. For 6 months I had 110 tilapia in there, with air bubbles. I'd exchange 50% of the water twice a week, using it in my garden, which was pretty happy with it (At farmer's market "Are your carrots on steroids?")

So recently my ammonia and nitrates have just been rocketing. With the cold weather I can't exchange as much water, plus the fish are so much larger, and I think I have a lot of muck on the bottom. So a couple days ago I added an RFF and biofilter that drained into a pool, and pumped back into the tank. Of course the problem with that is that it takes time for the biofilter to work, and my ammonia is still way off the charts (10ppm I think is the top color). All the water except the pump is being done by siphoning with hose scraps. Highly NOT recommended but it will get me by for a few more days.

Good news is only 1 dead fish in the last 3 months.

So I've got the greenhouse. Although a big fan of KISS, I see more flexibility of water AND bed management with the CHIFT PIST system. And because I want this to be a very small commercial enterprise, rather than a hobby, space is at a premium; and vegetables take up a lot more space in a greenhouse than fish do. So that means I want to be on the top end of my fish capacity, and so I will include the very small footprints of an RFF and biofilter in the design.

Layout is not to scale, is freehanded, and should be a little roomier in a 25 ft diameter greenhouse. FT is 4' x 4' (sorry about non-metric measurements), second fish tank to be added later, RFF and BF are 50 gal barrels, 2 large GBs hold about 400 gallons, 15'x3.5'x1'. Plus a third half size bed. Beds filled with nearby creek gravel. Duraskrim with some type of support. Looking like it might be 2 3/8" steel pipe bent to shape, lined with 2 x 4 supports and metal roofing sitting on 12" styrofoam. Sump tank partially buried, and water pumped from there back to FT.


The circuit starts at the 400 gallon FT, and I'll probably add another 300 gallon tank sometime in the spring/summer. Uses SLO with uniseals to go to RFF, pipe at top of RFF leads to biofilter barrel which is filled with used bird netting/trellis/straw bale net wrap. All that is 1 1/2" PVC and runs to the three grow beds. A bell siphon at the other end of grow bed drains bed when full into sump. 1 1/4" from siphons and from pump to FT.

Will plan to stock about 100 large tilapia and 100 small tilapia when other tank is added. Beds will mostly be used for lettuce, though I might experiment a bit in the spring. Probably add some supplemental lighting for the winter months.

Elevate the fish tank, bury the sump tank, and that would free up space for another growbed?

Sent from my SGH-T999 using Tapatalk [url='http://tapatalk.com/m?id=10']now Free[/url]

not shown is that the north half of the greenhouse is insulated, so the light is quite limited. I could push the sump tank towards the back (below the FT?) and get another 4' on the first grow bed. The sketch is rather rough.

If it were me, I would have the filter (not even really needed for this sized system) after the gravel beds. I like to give worms in the gravel some food. Also, make sure you have access all around those growbeds. 3.5' might not seem like much, but harvesting is much easier when things are within easy reach.

The solids filter or the bio filter? It seemed the BYAP forum leaned towards removing solids, but I never came to a sure conclusion except I am sure I don't want to be cleaning out the gravel beds in 4 years. And then there was limited discussion about mineralization and such...
Personally, I like the idea of having "dirty" beds, but not sure about that anaerobic layer that supposedly gets created at the bottom? Maybe a little sewer pipe at the bottom?
Am going for 2' walk space between beds.
Thanks for the comments, and I'd like to hear more opinions about the filtering.

If I wanted more N filtration couldn't I just put my bio-balls or netting in the sump tank?

well we're snowed in with temps falling below 0F (-20C) and getting fish tank to stay around 60 deg F

A week or two ago, I started losing tilapia. Not enough fresh water, and ammonia was spiking, must have been around 16 ppm. Did an 80% water change on a warm day and got the tank moved to its new home in the process. At about that time nitrites were starting to go up, so I think my filtration is starting to kick in. Ammonia has been pretty constant around 4 ppm since then.

The fish were pretty tasty.

So in the winter storm, I've started getting some work done in the greenhouse. Luckily I got some primary components together the day before the storm. Here's the pic from yesterday of the support for the first grow bed.

grow beds continue...and picked up my C-channels for securing Duraskrim from a friend today, plus two IBC's in town
except pickup truck wouldn't start, so not sure about getting enough gravel until truck does start

For some reason, my ammonia dropped, a lot, even without recirculation. Maybe the algae have stopped growing with the clouds and cold. Nitrites are a touch higher.

Hey aschwerin:

The bacteria will be slow growing in the cold weather, maybe that is a factor.

p.s. I really like your pictures and dome, it looks like it's in the same universe as this Tom Petty video: http://www.youtube.com/watch?v=ZTAhZKP5wCY&noredirect=1

In the last week...put in the Duraskrim liner with C-channels and wiggle wire. Pulled up the sides a bit so it wouldn't bulge out and the side braces would take some of the weight.

The big 8" pipe is temporary just to make sure I have enough room to play with my siphon.

French drain pipe and a sewer pipe scrap in the bottom. Intention is to avoid having that anaerobic buildup in the bottom, plus water is lighter and cheaper than gravel. I think I would have capped the ends of these pipes, but I will probably put them in the next bed too. I don't expect roots to clog the pipes 13" down unless I were to grow many fruiting veggies.

The neighbor loaded me some creek gravel, however it wasn't well-sized, and so I graded it by hand. I used the large (1"+) rocks on the bottom four inches. My smaller grade was mostly really fine so I found a pickup load of 3/4" round rock nearby for $20. That filled most of the rest of the bed, and I put the fines on top of that round rock.

I still need a bit more rock to finish the bed. I put the rest of the creek gravel on my driveway which needed it anyhow, and I will make a few trips or get the rock place to deliver me a few yards of that 3/4" round rock and I will use only that for the second grow bed.

Tilapia seem fine. They eat very little. I got a 500W aquarium heater, which does a lot more than the 100W. Their tank water stays around 64 deg, and up to 70 deg on a sunny day.

I put my sump pump in the bed and got my SLO installed on the tank so I'm just running full recirculation when its not too cold. Not sure why more people don't just put a pump straight in the grow bed, sure seems easy compared to fooling with sump tanks and autosiphons. Since I have two grow beds it would take two pumps and I think I'll just stick with the original plan.

Ammonia is very low and nitrites are up a bit. I don't have a nitrate measurement. My pH is high, maybe almost 8.0. It could be due to getting my cycling going, or traces of limestone in the creek gravel.

We're leaving for Christmas for four days, so I'll put the pump on a timer, and see where things are when I get back.