These fans actually do help to keep the summer tank temperature down.
We replaced the old HVAC for the house this summer, and the house temp became more stable throughout the house over the summer. The humidity is very well controlled by it that I no longer need my dehumidifier. However, I still heard the fans running after the HVAC replacement, though.
If I were to use the 4 inch fans on the ends of the canopy, I need to find something quieter than these on the canopy. Reilly complains about the noise of these fans. The noise resonates on the wood box and you can hear the high pitch sound throughout the whole house.
I will check the clearance in the back of the canopy and see if I can run two bulbs. I have two large overflow boxes in the back, and I have not been placing many corals toward the back of the tank. I am sure that the light will probably still help other corals in the center area.
I replaced my halide setup with LED's to avoid heat and frequent light bulb replacement. I suppose I can keep the ballast away from the tank to avoid extra heat input, but I hate the annual light bulb replacement...
