Excessive heat from lighting

[Reese]

I built my stand/cabinet and my cover and rigged up my lighting. The top is basically a box that stands about 8" with a hinged top. "Under the hood" is two VHO ballasts connected to 4 95W VHO bulbs (two actinic and two 10,000K). The lighting is for the one BTA I have and other(s) I plan to add. Pretty much the entire back of the cover is open with about 6" to the wall (cut out in two sections for overflow and returns). Oh and the tank is 75 gallons.

However, I'm afraid that I still need to use some sort of fan under the hood. Does one of those PC fans sound like it will do the job? And where would be the best placement of?

Thanks...

 

[Brenden]

I would probably put one on both front corners on top.

 

[melosu58]

I dont use a canopy. I use those mirrored metal covers over the bulbs

 

[ColdFish]

I have one of the low-end Coralife 36" fixtures on my 50-gallon which also has a canopy. It's 2 X 96 Watt (one 10K and one Actinic) and has 4 small fans built in. Heat is not excessive in the canopy, but it's definetly there. My heaters don't have to work very hard at all. Then again, you have twice the watts on a tank that isn't too much larger than mine. I would guess you'll definetly need some type of fans. On my fixture, the fans pull heat out of the fixture and blow it upwards. I keep the fixture positioned under a gap in the tank canopy so it has unobstructed air flow. Maybe you can rig up something similar.

On the downside, my new fixture (also Coralife) is 4 X 96 Watt with the seperate ballasts and is going on my 90 gallon, and the instructions with it were pretty emphatic about not installing it in a canopy