My opinion from this thread is that...as long as your in the reasonable range(76-82) You should be alright....
I believe the key is to KEEP YOUR TEMP CONSTANT
I keep mine at 79, but it gets as warm 80.6 in the day time...
When I first had my tank, my thermometer was broken...it showed the temp at 79, but it was 84!!!!!! for a few months. The corals all seemed happy, and they opened up alot....ppl would even comment on how gd the tank looked(ppl in the hobby/industry), so I think even high temps are ok, as long as the temp is consistent. Of course, the higher the temp, the higher the rate of evaporation.
I AM A FIRST YEAR REEFER.....TAKE CAUTION WHEN LISTENING TO ME