Thanks, you rock. Some people say thats too low, while others say its fine. I think its fine for my setup because of the amount of fans that I have, the open back, tons of water movement for evap., an extra 25 gallons for the sump/fuge, as well as the cold tempeture of the tank room..around 64 or so.
As for you, I think it should be okay as long as you have proper movement of air within the cannopy. 2 4" fans at the bare minimum. Air flow along the surface area of the water creates evaporation, what cools down the water. If you dont have great airflow I would go around 12" from water level. This might sound extreme, but is the best option, unless you can afford a good chiller for the tank. This is a big problem is you already made the canopy, but if not then it only just looks a little weird. Dang, that turned out long.
Im glad I can be of a help to this board, and if you have any concerns shoot em away! :yes: