question about controling heat

[Jeepman3sk]

So im working on my new 29g with about a 20g sump. I am planning on a 250w MH witha 10k bulb. I think ill need a fan can I just put the fan in the sump instead on the tank. I want to keep the tank looking clean looking. Im not doing a hood. Just a hanging MH.

 

[nanoreef58]

A fan blowing across the water level of the sump will be good