MH distance from water surface?

[tiffster]

I was wondering how close to the water's surface I could keep 250 watt metal halides. I've heard and read 4-12 inches, but that's a pretty wide range. I was thinking I could keep them closer if I used glass in between. Just need some input so I can get my canopy and get everything moved into the 55. Oh, I have the fixtures, fans, and I am going to buy 10000 k Ushios.
Thanks,
Tiffany

 

[jarvis]

I say 8 to 12. The higher they are can help with the heat build up and also keep the bulbs cleaner from mostly all of the salt spray.

 

[spsfreak100]

I agree with Jarvis, 8-12 inches is recommended. I keep mine around 10" from the tank.
I was thinking I could keep them closer if I used glass in between.
If you did this, the heat build up would be massive. The glass would trap the heat inside the aquarium raising the water temperature. You're best off keeping any glass cover off the aquarium and having the halides 8-12" from the water.
Take Care,
Graham