Do you feed every day. have lots of current? Maybe feed fewer times also give brine shrimp and some frozen and fresh foods. Fish need a very healthy variety. Just flake and pellet is not a healthy varied diet. But, vary the feedings and once a day is enough. Even missing a day once a week is good. Just make sure if fish are carniverous, or herb{algea} eaters. Maybe they are both. I am taking care of a neighbors tank that is inundated with red slime algea and three more weeks of this is not a good thing. Will have to get her ok on cleaning it off because her neons freak out as mine have done, and may never be seen again, just from working in the tank. MIne have not been seen for a month since I did a major algeal cleanup. I love those fish and miss them. My problem is phosphates. Need RO water but not in my budget. So I put up with it. Yes, I brush off red slime in my tank off the rocks but in my neighbors tank she does not have a bottom tank and everything just settles back onto all her corals and rock, defeating the purpose. Can't suction it all out, then new water has to be made up and she does not want a water change. We all have these algeal problems and can become a reals task, but there are remedies outhere. Check Steve Weitz or Wests site. anyone out there know his Email? He mentioned a product that can safely be used for the getting rid of these algeas and it does not affect anything in the tank, but the algea. I can not find the address again. Hope someone will answer this for you.