Hanging a pendant

[A_Lee]

Does anyone think that I may have heat problems over a 40g cube with a 250w MH hanging over it? I have a 150w SunPod sitting on my 15H, and the highest the temp usually gets is 79*F. Then again that tank is downstairs, and the cube would be upstairs.
How high should I hang the pendant above the surface of the water? Could it hurt to put an IceCap fan in my stand blowing across my sump in case any heat issues arise?
I will also begin keeping a 2L bottle of frozen water in my freezer...sometimes there are those rare, but amazingly HOT days in San Francisco.

 

[Gomer]

I have a 250 over a 40g and don't have heat problems. I do use a small computer fan though.

 

[Raddogz]

Have the fan blow across the display

 

[A_Lee]

I was hoping having the fan over the sump would save clutter on the main tank. It would make sense to have the fan to blow across the surface of the tank as well though, because not only would it promote evaporation, but it would also minimize the heat that reaches the tank from the MH. I think I will do that. I just need to find a fan that clips onto the side of the tank ... maybe one of those Azoo ones.
If I really do have heat issues, I can just have the fan come on whenever the fan comes on.

How far would you all hang the pendant above the surface of the water?

 

[tuberider]

I have a 250w over a ~45g tank with no heat issues other that ambient room heat, my sump has a fan on a timer that blows across it from 8 AM till 10 PM. I've found the fan can pull down the temps at least 4 degrees.

 

[phishphood]

Shouldn't be a huge problem with the heat. Blowing the fan across the sump would work fine. You can either set it on a timer to come on a little after your halides do if you notice you're consistently having a problem with heat, or just set it up on a temp controller if you can get your hands on one. I wouldn't bother with a PC fan/icecap, etc (just IMO) but a simple $3-$5 clip on fan from target/wallymart etc would do just fine.