Currently im using a 1,200 gallon Doboy ( sorry if i misspelled it). Me and my uncle built 2 seperate 100 gallon plastic containers for filters, from the two drain holes that were already built into the liner, which we pull the water out of the pool with a pump, we filled the containers with bioballs and sponges ( sponges from the 99 cent store) and we use a pond water fountain for the water coming back into the pools through pvc pipes. Lol it looks really ghetto but the entire thing is our two car garage. I was having a lot of problems keeping the water to the temperatures i needed so we also set up actually heaters in the garage to keep the garage right around 80 degrees which keeps the water right around 76 inside the pool and 74 inside the containers, currently i have 4 silver arowanas around 24 inches long and 4 red belly pacus around 24 inches long, i have 9 oscars all around 6 inches long, 3 jaguar cichlids all around 6 inches long and a RTC x TSN around 6 inches long and everyone dont laugh i have a 14inch channel catfish we caught from lake meade that ive had since it was six inches long.