Hi, everyone!

I am from northeastern Ohio and built a greenhouse last fall with a 1500 gallon built-in tank that I hoped to raise fish in. The greenhouse is going great and I have a lot of spinach, lettuce, beets, broccoli, peas, cauliflower, parsley, basil, tomatoes, squash, flats of flowers and other vegetables, etc, started.

The fish part of the dream, however... I am beginning to wonder if it is too much expense, etc, to be worth it. Maybe you all can help me figure out a cheaper way of doing what I want to do.

I don't care if I end up with very intensive culture - in fact, I actually think it would be better if I didn't because I think intensive culture will make the operation too susceptible to a quick "crash and burn". So, I am thinking to include the following in my set up:

- a 1500 gph circulation pump
- possibly some sort of water heater element
- a waste water storage tank (plastic barrel)
- a combination biofilter and solids filter where I was thinking about using this expanded plastic fiber material that comes in sheets and put a fairly fine mesh on top, then pull the top filter out ever few days and shake it off and rinse it in a smaller tank. The solids would fall off in the small tank and I'd use the pump to pump that gunk and water onto my vegetable beds. The biofilter would help to dissolve some oxygen into the water because it would be elevated above the fish tank and water would trickle down through the pads. I plan to use some sort of vacuum attachment on the pump to periodically vacuum the sediment off the bottom of the fish tank and instead of sending the dirty water to the biofilter, I'll divert the flow when I'm vacuuming either to the vegetables directly or to the waste water tank.
- I know that this method of aerating is not going to allow very intensive culture but I have seen a koi-raising operation where all the guy had was biofilter pad material but I don't think he had a bubbler of any sort.

Down the road, if I get the fish thing working well, I would like to fill in part of one of my raised beds with gravel and use it for aquaponics and grow some lettuce.

Question: I can find the pump and heater coil I want pretty reasonably but the thing that is surprisingly expensive is the biofilter pad material. Does anyone have any ideas on an inexpensive way to build a biofilter/aerator such that I can just limit the major components to a pump and biofilter? Any ideas as to the volume of biolfilter required?

Thanks and great to be here.

Wes