check this out, you'll really like it. It's a method of growing food (or plants in general) from fish effluent.
www.backyardaquaponics.com You don't do water changes... in a well running aquaponics system the biological filtration resembles what's going on in nature. I'd drink the water in my aquaponics system over what comes out of the tap
You mentioned that your system is inside. You'll need some good light to keep plants thriving enough to remove ammonia, nitrite and nitrate from the water in any measurable amounts.
Anyways, here's a picture of my aquaponic aquarium.
The pot on top the aquarium is filled with gravel and there's a bell siphon buried in there. That tiny pump fills the pot up with water. Once the pot is full, the bell siphon will kick in and drain the pot. This sucks air down into the gravel which has a lot of surface area. This oxygenates the water very well.
The constant agitation of raising and lowering water in the gravel will break up any debris that gets pumped into the pot. Bacteria in the gravel converts the ammonia into nitrite then other bacteria convert the nitrite to nitrate. The plant on top sucks up the nutrients. I've also got some red wiggler worms in the gravel and they'll also eat up any solids that end up in there.
My set up works alright. There's no ammonia or nitrite detectable in the water, it's 7.5ph but my nitrates are pretty high. Problems with it are... the plant is a pothos, it's not really a high nutrient user. It's in a north facing window and doesn't get nearly enough light. The pump would probably be better if I had it along the bottom of the tank. I think if I had more light and a heavier feeder of a plant the nitrates would be undetectable as well.
