I have a 250 fish tank with 14 goldfish (the 15th leaped out and petrified on the gravel) and 2 algae eaters. I have one 50 gallon growbed. I cheated and added bacteria to the system to add fish quickly.
My growbed is filled with lavarock and I added red wiglers to take care of the solids. Everything
is working wonderfully and the fish seem very happy. I shaded the growbed and the fish tank to
limit extreme water temperature fluxuations.
I have peppers, sweet basil, tomato, cucumber and lettuce in the grow bed all in a 12 x 12 greenhouse.
Even with shade cloth, it still reaches 100 degrees but the lettuce thrives anyway. Amazing!
I am hooked and want to expand. I have seen systems with the raft system that require solids to be
removed before going back into the fish tank.
Is it possible to place the growbeds in the water flow between the raft and the fishtank to act as filters and utilize all solids?
yes, that is called a media / raft hybrid or integrated system design. and i my opinion its the way to go!
i will say that in Texas you want to remove the plastic from the greenhouse and go with just 60% shade cloth.
i like the idea of the in ground greenhouse... im pretty sure there is some documentation of the guys that do that out there on the web somewhere.
Yup, entirely possible and I concur with Rob... definitely the way to go!
In terms of square footage of grow space in my hybrid system, I used about 25%-30% media beds to 75%-70% DWC (the more media the better...my grow beds are about 16" deep) and have not had any issues with solids build up. (I run a pretty low fish load though). You might want a higher fish load, so check out Mr. Nash's "polisher" to take care of the fines that might make it through. Or leave yourself some wiggle room in your design so that you can later add a swirl filter should you need to (I've not had to add one and my hybrid system has been running a couple of years now)...
Thank you very much for the info and encouragement. I am attempting to design a retractable roof tor the summer that would encorporate shade cloth for summer and polycarbonate for winter to grow year around. I got the idea for the below
grade greenhouse from a pratice gardeners use in Bolivia. Underground houses are much easier to heat and cool also.