Great big tank

[maintainer]

Hi all, I'm new on here, and have been reading allot before I posted anything. I have posted on another site about this subject, and I hope it's alright to ask the same question in two different places.
Anyway, I have a big concrete manure tank (20ft x20ft x 8ft deep, with a roof) on my farm that hasn't been used for that purpose in many years. It's basically just a water tank right now. I plan to drain it and clean it up, then grow some fish in it. Some questions I have are....
How many fish could I raise? How much fresh water needs to come in to keep fish healthy, and how much aeration would I need? If I have a constant supply of fresh water "running through" do I need to filter the water? I have a little run of water out of the woods that is a little low in PH, could I run it through some limestone to help with the PH as this is my "running water" that I plan on using (I think it will work)? Should I try to raise a few different types of fish and section off the tank? Or could I put different breeds together?
I know this is allot of questions, but I appreciate any responses. Thank you.

[GaryD]

Hi Maintainer,

Welcome to APHQ.

Anyway, I have a big concrete manure tank (20ft x20ft x 8ft deep, with a roof) on my farm that hasn't been used for that purpose in many years. It's basically just a water tank right now. I plan to drain it and clean it up, then grow some fish in it.

Doesn't matter how you cut it......that's an asset.

I calculate it to be 3200 cubic feet capable of containing just under 24,000 US gallons.

Using it as a fish tank poses some challenges......like accessing the fish and ensuring that solid wastes generated by the fish can be removed from the tank.

I'm not suggesting that you can't use the tank but rather that it needs careful consideration.

Is it just a pit........or is above ground? What access points do you have?

Any photos?

I'd need to know a bit more about the tank before I respond to your questions.

Gary

[maintainer]

Here are some pics. The front wall has a sliding barn door on it. It's not too pretty. How often would I need to pump out the solids?There is a drain pipe in there, it's just not actually a drain to empty the pit, but to fill it up from the barn gutters that are not in use anymore. I have a small backhoe that I plan to use to dig up and reconfigure that pipe to use it as a drain.

[Pugo]

Looks like it has could be converted into something. You may want to thing about dividing the tank in several small tanks, all with bottom drains. As you will need nursery tanks , grow-out tanks, as some fish grow faster than others so you will need to try to keep fish that are the same size in one tank. Then you will need to workout filtration for the system, and aeration, None of that is very difficult to do so don't start worrying but not as easy just dropping fish into it.

I guess if you didn't want to do to much you could dump some catfish into it, and grab a fishing pole when you wanted to eat fish..

[Cecil]

Purdue University has a CD on converting manure pits to fish tanks. I can get the contact info and price if you're interested.

[JohnMc]

Maintainer,

Wow. Lust comes to mind but I don't think I will be shipping that to Texas.

If you are considering a run to waste system you might want to talk with PA Department of Environmental Protection. PA does have water quality standards you would need to adhere to. Do you have a way to second use the enriched water on the farm in some fashion?

There would be serious $$ (fert) to not utilise it.

[Cecil]

John do CAAP standards and NPDES permits apply to aquaponics too?

I know with my small aquaculture farm I don't have to worry until I reach 20,000 pounds of fish or use 5000 pounds of fish food per week even though I discharge from my trout pond overflow more than 30 days a year.

[JohnMc]

Cecil,

Probably not since AP is a recirculating system. PADEP would probably be interested in the backup plan if one were using above grade tanks in the event of a failure. Only reason I brought this up is that from what I gather maintainer was thinking a run to waste configuration.

[maintainer]

John, please excuse my lack of knowledge in AQ, but, I'm not sure what "run to waste" means. Do you think the water in the tank and the draining of it is an issue for DEP, or do you mean after I start raising some fish and just letting the water run out (I guess this is what you mean as "run to waste")? We do use the manure that is produced by our beef for fertilizer, and I'm sure I can figure a way to capture my new manure too.

[JohnMc]

maintainer,

You have the jest of it. Catfish farms in the south divert some river source into ponds (tank in your case). They then outflow via pipe back into the same river down stream. The excess feeds, effluent are dumped out in the process. Hence run to waste.

maintainer, I don't know where you live exactly so this may not apply to you. The eastern half of PA, NJ, MD, VA & DE have federal watershed guidelines to try to protect the Delaware and Chesapeake estuaries. Much would depend on your proximity to a river.