My LFS said that a refugium with mangroves and macroalgae (Actually they only mentioned mangroves, though I added macroalgae just to help out), live rock, a protein skimmer, and a powerhead were all you needed to maintain a tank. I guess all I have for filtration are the refugium/sump, the sponge surrounding the drain flowing into the sump, and the sponge surrounding the pump pumping water back into the tank.
The drain flowing into the sump is receiving water from a continuous siphon overflow.
Is this amount of filtration sufficient, or would I do better with a little more? I've heard things like bio-balls aren't necessary.
Also for the second question, should I clean the sponge filters around the drain and pump, and if so, how often? I've cleaned them before, and noticed they make the water turn a cloudy brown color, which I don't think would be good to have. I have, however, heard of keeping beneficial bacteria on the filters, which cleaning them off might remove.
And a third question: When I do clean the sponge filters and put them back, I notice the water in the main tank gets a little cloudy-white for about 10 minutes, before it goes back to clear. What could be causing this?