Those fans are cooling down the light bulbs, not causing evaporation. Evaporation cools very well, all you have to do is keep the front part of the lid open. If you need more than that, you can get a little clip on fan to run across the water. You can reverse the light cycle and leave the lid all the way open during the day, this will help a lot. If you need even more, you can have a fan on it, if you do this, make sure to have a heater to balance the fan running non stop, and of course you have to make sure to close the lid before the lights come back on.. All of these except reversing the light cycle will require you to add more topoff.
Water temperatures at or above 85F can cause bleaching, so can large day/night temp swings.