A couple of things I have noticed. A temp of 81-82 degrees results in rapid development of my clownfish larvae. Instead of hatching simultaeously on D8, 1/3 hatch in the wee hours at the beginning of D8, continue to hatch throughout the day since they can no longer fit in the egg, and the remaining 1/3 hatch the night of D8. A real pain to catch larvae. I put the tank back down to 78-79 degrees and all is right as rain. 1 hr after lights out on D8, all hatch together. Interesting comment Ed, I have also heard that a higher temp lowers Oxygen, no doubt this is true, but whether this has any real effect on coral growth, etc, I do not know. As a side note, an overheated tank ie 90+ degrees will drive out a considerable amount of gas from the water. 3-4 weeks later, and a few of my LPS still have internal air bubbles that have not redissolved or been able to be force out. Its a coral version of "the bends".