:thud: I have a 75gal FOWLR tank with just 4 small fish. I lost a Yellow Tang and a Queen Conch just recently. Now my tank is getting really dirty, the algea is getting out of hand. I change my water at least 1 time a week with RO from my LFS. I have a variety of a few snails still left but, I just wonder if my problem would go away if I got another Queen Conch or was it my Tang that kept it clean? My sand is so dirty I need to get something real soon. And what I have don't seem to be working hard enough.