I have a 55 gallon tank that has been running for 4 years. but just 2 days ago it got really cloudy. i have 2 filters in it and 4 fish, a small red tail cat, a bull head, an oscar, and a knife fish. and i just bought a big pleco for it because there is a lot of algae growth on the side. is it just an algal bloom, or something worse. it also does get some direct sunlight. and before anyone tells me yes i do know how big a red tail gets, same with knife fish.