i have my lights at least 18 inches awap from my corals, i have 2 400 watt MH, on a 46 bow. it might be that they got burned. i was in canada for a week and my dad was taking care of my tank and when i got back i had so much brown algee and my solinidy was over 3. everything came back exept my CAP and some zoos. i was wondering if they would ome back or not. i did have alot of zoos come ack though.