what fan for the canopy?

I am about done with my DIY canopy. I still need to stain it and install the light. Im going to be using one 175 watt Iwasaki 15000k MH bulb and a reflector. I need to figure out what fan to use. Are computer fans good or should I use a small clip on from walmart or something.

Here are pics of the canopy I made today.


i have a 265 with 3x250w 14k halides. I have 2x120mm tricools with blue led's exhausting air from the canopy. It's ok but should have done four. If you dont mind holes in the top i would say 2 would do it for you easily and you get free moonlights. But if you want them on the back you get some moonlighting. on a side not 2 fans with leds light my tank good enough so maybe 2 on yours might be too bright. Plus you need a wall wort 12vdc ps which can be found at radio shak pretty cheaply.
I plan on installing the one fan on the side of the canopy blowing in. The led fans would be pretty cool though.

I ended up getting this fan at radio shack. I hooked it up to a power cord and its ready to be installed. Hopefully this thing moved enough air.

I would run a Minimum of 2 fans, 1 drawing air in, one pushing air out. You can run with 12V or 120 V fans but make sure you have a good ground on the 120V fans. I have a 5' x 2' canopy with a pair of 250W MH's and 4 T5's and just 2 fans keeps the temps very reasonable. It will however increase the evaporation from your tank. I would also suggest getting the little foam filters for the fans as those are much easier to clean than fans..
I picked up a 2 fan unit on ebay for about 18 bucks. I have mine mounted on the left side of the canopy on the back with the right side open for air movement. Seems to work well.. my chiller did not turned on much during those couple of warm days we had recently. I broke the mounting clips, but not an issue i just need to go to the depot to get some new ones.. I was moving the canopy and the unit got caught on the back... yuck..

these are what I have in my DIY canopy...I have 3 fans in the back (2 blowing in and one out) I tried to get the temp control to work but it just didnt work how I wanted it to so I installed the manual controls....I am very happy with them