Is there a type of algae that makes the water cloudy. I have had algae growing on the side of the tank and I have learned how to control it. But as of recently i have had some cloudy water problems. It has a kind of green tint which lead me to believe that it was some form of algae. i have done some massiave water changes to try and defeat it but it continues to come back. When I test my water everything comes back fine so it doesn't seem dangerous to my fish. Right now i have cut the time my lights are on to see how that helps. If anyone else has had any issues with anything like this I would like to know what you did to fix it. Thanks for any help.