mh's how high up

[teog]

how high up should metal halides be off the water? and is it dangerous for al living things if they were placed closer to the water?

 

[wamp]

I keep my halides about 7-8" off the water. This prvides space for air to flow and also room to work in tank without getting burned.. Also, you do not want water to splash on them. They might go BOOM if it does..
I keep as many corals as I can fit directly under them. Some corals like High light, They are at the top. The ones who don't, go at the bottom..

 

[glazer]

My question pertains to this as well so might as well use the same thread. I am setting up a new tank... building the stand and canopy. I am having a hard time finding any concrete info on HQI (double-ended MH's) as far as their operating tempature. My existing tank has a 250 watter in it and whoa does that thing put off some heat! The canopy is 12" tall though which puts the bulb approx. 10.5" off the water surface... heat hasn't really been to much of an issue, I do have to turn on a small fan once in awhile but all in all no prob. All I have seen info wise is that the HQI bulbs burn cooler, well what does that mean... a little, alot? One site that I came across made the statement "50% cooler than standard MH's" Can that be right? I would truly love to get a lower profile on my canopy, for asethetics... nothing like having a two foot tall tank with a one foot tall box on top, hehe So anyone switch over to these bulbs that can give me an idea on the heat diff? Thanks