Tank was given to me by a friend, I think it's between 40-50 gallons. I'm running dual 20 gallon filters, with dual air bubblers. 3 bass, one's 3 inches other two are about 7 inches. One war mouth, one crappie both around 4 inches. A gourami and a rainbow shark, and 3 blue gills about 2-3 inches...