(I think I already know the answer to my question, but just to be sure....)
I just bought a clip on cooling fan for my hexagon tank, as my new clip on metal halide has been causing a large amount of water evaporation. The bulb/light is extended right over the middle of the tank. Should I have the fan BLOWING air or SUCKING air? The way it's manufactured appears to be designed to SUCK the air, but wouldn't BLOWING be more effective?