Wondering what would be better for my low tech moderately planted 4' tank. I'm am either going to get a power head to help increase flow or a air pump sponge filter. Currently I'm running a 75 gallon filter on my 55gal. I am also gonna get a fish. I want a fish that will help clean algae off my plants. I was thinking about a red tail shark. I was thinking the shark because I have a 4 1/2" leopard centapoma who will eat anything that fits in his mouth. Its makes things challenging sometimes but maybe my favorite fish ever. Over three years old and still looks great. Other fish are a small school of rainbows upside down cats nothing else that would cause problems. Any thoughts??