Backyard Aquaponics
A place to discuss aquaponics

I designed and built my greenhouse by myself, but the tank was the exception. I had a very experienced concrete contractor (3rd generation) do my tank.
He used forms braced inside and out with no thru rods. He used a six bag mix and a plasticizer compound. A very important addition was a vinyl seal strip between the floor, which was poured first and the walls. This strip was about 9" wide with ribs. That meant no leak at that seam. The tank has had no cracks or leaks so far.

I thought I had leaching covered because I used a Radon sealer on the concrete. This chemical bonds with the concrete to close the pores and stop Radon gas from passing thru. Surprised me when I had this problem with alkalinity.

I have sent an e-mail to sales at Express Polymers. The on-line information looks very good.

Make that 12ish years
No C1 I just am into overkill sometimes, especially when it was a pig to dig in and I didnt want any more maintenance.

Thanks Dave

I talked to tech reps at Sani-Tred and did a test kit on my tank...it worked

Now I have done my concrete tanks(2) with Permiflex and today I am checking my work, which finished 8:30pm yesterday. It rained, sleeted, and snowed yesterday, but I was at the bottom of my tank in my greenhouse rolling on Permiflex coats one and two. The second had to go on while the first coat was tacky, so you can not spread the work over nite. I will wait four days and then wash down with mild detergent and rinse. After that I can refill my system to get ready for my next batch of fish coming May 9th. That will be 200 channel catfish, 200 hybrid blue gill, and 50 perch. Need to get my bacteria going. I will use the ammonia system. Put in 5ppm ammonia and circulate water until ammonia and then nitrites go down. Then add a little ammonia to feed them until the fish take over.

The total cost was $438.00 for four gallons of Permiflex and catalyst and one gal xylene for thining. Rolled on with good quality 3/8" nap rollers (one for each coat). I used half a gallon of xylene to thin the Permaflex as suggested by Sani-Tred techs because the temp was 50F and that makes the permaflex too thick to properly penetrate.

Here is another view

I hope it does the trick, sounds like you're back on the BYAP pony!

This is the tank with two coats of Permaflex.

Well it does look good. Hope it works well.

Nice work Doug

Thats not a tank. Its a raceway or at least a lap pool

Looks great to me. With your designed freeboard (assuming that is the blue line) how many gallons does the tank hold?

Also, I was wondering if you grew the female green sunfish x male bluegill hybrid. That's the most common that I am aware of. I produced some of those years ago. They did okay until an employee killed them. I recall the hybrids being very aggressive feeders.

Werent we avoiding Xylene ?
I remember someone telling me if I go with Fibreglass , avoid the stuff with xylene in it ..

DB, that really is a nice tank. Is the small compartment going to be the sump tank?

The contractor that poured the tank said " when you tire of raising fish, that will make a great lap pool"

Yes, they feed agressively and that is the type of hybrid I have. You can see my highest water line in the photos and they still splash water out while feeding

I run 3200 gallons in the tank and about 800 gallons up in the growbed/filter system. If power quits, that water in the growbeds does not flow back to the tank because of standpipes in the grow bed (about 100 gallons does flow back until the level goes down to the stand pipe). When I startup the system, I run about 2000 gallons in the system to keep the nutrient level higher for the plants and I do some foliar feeding with a seaweed and fish emulsion mix.

Good point. The Permaflex itself is food safe. Adding xylene changes the toxicity. xylene is very volatile and most will evaporate during drying. I had all doors and vents open and fans running. I will be interested to see if there is any odor after 4-5 days. Odor would indicate that something is still being emitted. If the odor is gone, then I will wash the tank with mild detergent, rinse and fill the tank and start the ammonia cycle to develop the bacteria. I am running against a tight schedule because the fish arrive on May 9th whether I am ready or not.

No, I have a Rubbermaid 100 gallon tank as a sump under the grow table that then gravity drains into the big tank. The only pumps in the system are in the smaller tank you are asking about. There are two 60 watt pumps in parallel. Only one runs at a time under computer control. So I alternate between the two. Soon I want to sense the water flow from the pump output so I can detect a failed pump. Right now I do not know if a pump fails, but every 15 minutes the "on" pump alternates. So I would have flow about half the time which should keep everything alive until I see the problem. I have the pumps running from an inverter on two deep cycle golf cart batteries. The batteries are charged by a charge controller meant for solar panels. Someday the panels may cost what I can afford and I will buy them. Until then I run the charge controller from a 120vac power supply at 15 volts/25 amp output (3000 watts). The control computer is a Rabbit RCM3400 embedded controller that is also run from the batteries. I figured that the system would run for about 12 hours on the batteries. So I tried it by pulling the plug and watching the system. At this point it failed after 8 hrs and 22 minutes. The embedded controller recovers after power returns. We have had a few multiday power failures (rare) that would kill all my fish if I was away.

The smaller tank has two purposes and they are somewhat conflicting (never perfect is it?). I have a multiple year program for raising fish, so I need a tank for fingerlings arriving when I have semi-mature fish in the big tank. The big tank feeds water to the smaller tank by syphoning(sp?). The fish stir up the sediment in the big tank and that flows into the small tank where it settles. That makes the small tank a settling tank for solids which is not good for the finglings. So far I have only started clean with fingerlings without any larger fish and I put them in the main tank initially. Now that I see the sediments build up in the small tank, I think I will not be able to use the small tank to start fingerlings as I originally planned.

Well, I sure got long winded here

Seeing as you might want to keep new fish isolated/quarantined for a period of time before putting them into the same water as your more mature (and therefore bigger investment) fish it would probably make sense to set yourself up something of a quarantine tank with it's own filter/pump that can be tied into the main system after an appropriate quarantine period. Of course I expect you are pretty tight on space in your greenhouse so I don't know how you will manage this.