opinions on MH for 29g

[Paradoxed]

wanted to get some opinions on a metal halide setup I am contemplating building
36" Build It Yourself Retrofit Kit from http://www.hellolights.com/36builityour.html
250w ARO Electronic ballast
I have 2 55w pc lights now and will use these with the new reflector.

I am wondering if I need to redo my hood, have a 4" fan on the side not show in the picture, light will be a bit close to the water, hard to estimate, I figure about 4 inches

thanks

 

[Unarce]

4 inches is really close for MH. 6 inches is the recommended minimum and I keep mine 9 inches from the water.

 

[hillbilly]

I agree. 4" is really close. Honestly, I don't like canopies with MH. High wattage lights sure put out lots of heat that you will need to remove. Hanging lights over the tank works much better. Having said that, you may need to add another fan so you can have one at each, to pull cooler air through the canopy and out the other side.

 

[Modo]

Speaking from experience, you'll want to have at least 8-10" between the bulb and the water's surface.

I used to run a 250W Iwasaki and 2 NO Flourescents over a 29g w/ no sump and had a constant temp of 80-82max in the TX summers. Of course that was with the AC set at between 75-78F. I only achieved 82 a few times. I believe you could get a cooler temp if you had a sump and higher water volume.

I had a 12" canopy with an open back and 2 3" fans blowing on the surface of the water. This is very important for a tank this small. You'll need the evaporation to cool the tank. Don't try to draw air out, blow as much as you can inwards and directed at the water.

It was also helpful to have a vent ( I used a large drill bit to drill several holes directly above the reflector) above the light to have the heat dissipate directly upwards. The air blowing in the open back would circulate off the surface, up the inside of the door and back out the top.

It can be done, but you gotta watch it. Good luck and let us know how it goes!