DIY canopy questions

[reefr]

I'm building a canopy 48"L x 14"W x 10"H I'll be using 2 250W MH (mogul base) and 2 96W PC's the canopy will be hanging above the tank at adjustable heights, my 2 questions are:
1. Should I put a glass or acrylic cover?
2. I will have 2 fans 1 blowing in the other out, what CFM should I get on the fans?
Thanks in advance for your input.

[Geoff]

since you are using SE bulbs, there is really no reason to put glass or acrylic covers on them. this is even more true since you will be hanging the canopy instead of resting it on the tank, so you can adjust the height. my 400w were only 8" above the water and have not had a problem.

i prefer to run all of my fans blowing out. more efficient use of the air. this can however corrode the fans faster, but i think it keeps things cooler.

G~

[reefr]

Thanks Geoff,
I'm replacing an CSL hood that has a acrylic cover and is a pain to clean it up all the time from inside the hood (dust) and outside water splash and salt so you think I'll be allright at 9" above the tank without any cover?
Thanks again!

[Loverotties]

That should be good!I like having fans on both ends going same way to pull it threw at a faster rate keeping it cooler.Every one has there own thinking!