I took apart a 125 gallon tank that i chipped real bad. I have decided to build a tank for my son with the glass. I'm making a 21"x21"x18"h aquarium. Building the tank is easy but i'm trying to figure out what kind of filtration I should use. The tank is going to be FOWLR. My son wants a porcupine puffer and some tangs. Do i need a sump or can i get away with a canister filter? I'm using 3/8" glass so I'm making it rimless. I've drilled tanks in the past so i'm not afraid to drill. Any advice on fish is welcome to. I'd like to leave it rimless so i'm looking for non jumping fish. not looking for carpet surfers. thanks in advance for all your help.