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Speedway_06
10/03/2007, 02:45 PM
I am planning on putting 2 175w MH's above my 90 gal (48" in length). What is the proper height above the water these lights should be? What is too high? What is not high enough? Thanks in advance

MegsB
10/03/2007, 03:37 PM
well all the canopy lights i have seen with MH in them (my 2 included) sit about 6" above the surface of the water (as the legs are about 3" long, then a few inches to the top of the water) so i think that is probably standard

kysard1
10/03/2007, 03:46 PM
thats way too close, you don't want the bulb any closer than 6-8 inches

Speedway_06
10/03/2007, 03:49 PM
Well, I built my own stand and canopy, and the canopy is 16" tall with out a 1/2" overhang over the tank. I have plenty of room but don't want them too close to the water so that I can avoid overheating the water, but I don't want the too far so that I lose intensity.

bertoni
10/03/2007, 03:49 PM
The height depends on how much of an overheating issue the tank sees, and how much light the animals want. Also, if the bulbs aren't shielded somehow, keeping splashes of water off them is a possible concern. I've run with MH anywhere from 3-4" off the water to much higher.

Randy1
10/03/2007, 04:17 PM
Think about going with 2 250 watters instead of 175 they don't cost much more and give you more options. I run mine about 10in. I had them as close as 2 once and a few spashed and broke the glass and bulb. And yes the bulb was only a month old. My corals really had better color at 10 in. above the water than 2in. belive it or not.

kysard1
10/03/2007, 04:31 PM
You may be better with the 175's instead of 250's if you like the Iwasaki 15k. There isn't a SE 250W over 10k that matches its output. I wish I had gone with 175's.