Hi fellow Aquarists, I bought a megaflow sump with bio-balls. It will be setup with my 90 gal tank. I wanted to get some opinions on the bio-balls,... should I keep them in my sump or remove them. I don't know to much about them and what they do but I hear that they will help my Tank. What do bio-balls do and why are they helpful? if they are not helpful tell me why they aren't. Thanks your opinion it is always appreciated.