Almost 3 years. I have a blue chromis, clown fish, blue spotted puffer, coral beaufy, green star polyps, and an anemone. The coral is on the other side of the tank from the other stuff, I have 2x 175 watt metal halides and 2x 40 watt flourescent lighting, nothing else is really affected, but I just had a brand new (friday) yellow tang pass away this morning...I have to test my water...going to do that now.