I recently stumbled upon this paper on R2R - http://www.ronshimek.com/salinity_temperature.html It covers temperatures in coral reefs and how it affects calcification. Particularly, this bit seemed interesting: If you were to take a survey of where people kept their tanks, I would guess a majority would be in the range of 77-79. I personally let mine fluctuate about 4F and fall anywhere between 78F and 82F. So where do you let your temps fall? Do you mind a large range of temps? Do you keep it precise as possible? Let me know!