I have a 55 gal fish only tank that uses a wet/dry filtration system. It seems that I am always having to clean the glass, crushed coral substrate and equipment to get the brown diatoms off. Initially I used snails to combat the problem, but they just don't last very long. Currently I have a Flame Angel, a Percula Clown, a Fiji Devil, a Banggai Cardinal, a Purple Tang, a Cleaner Shrimp and a few hermit crabs. I am not looking to add any more fish to the tank. My water has been hazy or cloudy since day one, about a year ago. My local fish store has recommended a UV sterolizer. They have always had good advice, but I thought I'd ask the guru's on this message board first. Any thoughts or comments would be appreciated.