I recently received a 60 gallon (I think) tank that needs refurbishing. The dimensions are 30” L x 18” D x 25” T. There are some .5 in there but don’t remember where! I want to only use a sponge filter but I’m not sure how I should set up. I plan on getting an Aquarium Co op one. Should I set up one large, two medium, two small, or three small? I plan on a multi tetra community or angel community. My current tank is a 20 long with one elderly Betta and 9 tetras (slowly building).