where to aim fan?

[gatsby174]

I am having some troubles keeping my tank temps down and need a fix until I can get a chiller. I bought a smaller fan (like for a window) and couldn't decide to aim it at the sump or the top of the tank. What do you recommend for the most ability to cool the tank? Thanks,

[rkelman]

Aim it across the top of the tank so it blows down the length of the tank. Oh I see you have a cube so I guess it doesn't matter which direction on your tank but still tank is better than sump imo.