Building MH Canopy. Need Some advice

[rye22]

Hey guys i am building a MH canopy with two 250 watt 14k bulbs

i was wondering what kind of cooling fan should i get to keep the canopy cool?

What brand? how big? how many?where to buy?


my tank is the standard 75 gallon tank


Thanks guys

 

[sfsuphysics]

Well depends how air tight your hood is..
I would probably go with a couple computer fans at most, quiet, low power, and cheap.

However I would first see if fans are necessary for cooling. Your halides might not warm your water up as much as you think, however fans for removing moisture probably would be a good thing.

 

[rye22]

how high should i place the halides above the water? my tank is 24" deep

 

[Gomer]

very very dependent on your reflectors. SOme can go a few inches above, and some require ~12-18"

 

[rye22]

i have these

http://www.hellolights.com/index.asp?PageAction=VIEWPROD&ProdID=530

 

[Gomer]

6" or there abouts should be ok. I would test to confirm the spread coverage though.

 

[rye22]

isnt that pretty close?

 

[Gomer]

The bottom edge of the reflector 6" above water line...perhaps. perhaps not. If you have no shielding between the bulb and water, you'll want to go higher for spray reasons. Is it too close for spread, that is hard to tell but it may be right. Again, try it out over your tank before putting hard work into an enclosure

 

[rye22]

ok thanks..

now how about some fans

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010110573%201372726528&bop=And&Order=REVIEWS

which ones should i get

 

[Elite]

6"-8" from the water surface to the bulb. That how high I mounted mine. I use 1 150W over a 40G breeder now so I have to mount it higher so it can cover the whole tank..

 

[sfsuphysics]

I personally wouldn't worry TOO much about how high your bulbs are from the water.

First I'd make sure that your hood you design is useful, i.e. will you burn the hell out of your arm if you need to get in the tank? Your bulbs are too low! Or you need to design some way to raise the bulbs or move the hood out of the way.

Then when that's done I'd just make sure a good portion of light gets into the tank. I.e. you aren't brightly illuminating the floor around your tank

 

[Elite]

Mike, I think he wants to get a general idea how high people mount their light so he know what to aim for. It's not easy to adjust how high or low the light is when you have a canopy. One thing good about having a canopy is you don't get any light on the floor ;D ..

 

[rye22]

does anyone have some good examples on some designs of some canopy that would work good

 

[sfsuphysics]

If you want to go way out there, check out Bryan's design (SeminolaCPA) in the member's tank sub-forum

 

[seminolecpa]

Hey.... its's not that way out there.

Be careful though if you get into the Luminarc type reflectors AFA distance from the water. You can get a concentrated "spotlight" effect if they are too close.

 

[Gomer]

Lumenarcs iirc, need around 12" and lumenbrights around 18"

 

[sfsuphysics]

Well it's way out there in that it's a front hinged transformer canopy that turns into a defender of Earth!

 

[Gomer]

UNICRON!!!

 

[rye22]

anyone have some suggestions on some cooling fans?