glad to hear things are looking up for you Sparky!! i am going to take a few wild guesses in case these have not been mentioned, #1. maybe its your ballast? i dont know much about them but im sure they can be faulty, you switching tanks/lighting makes me wonder how old yours is on the 90. #2. i just got some frags from a fellow reefer up here who had the same die off and algae bloom as you a few months ago, and it turned out a dime was decaying in his system, he lost most of his corals but no fish, anyway someone could have thrown some change in our tank or it fell in there somehow? i think he said his roommate did it before he moved out, apparently they were not getting along.