Lighting distance

[tigershark]

I have a 60 Gal tank with a retro kit to hold 4 VHO bulbs. I turned them on this weekend and notice that they get pretty warm. How far above the top of the tank should they be so they dont melt the tank or heat the water up too much? I have a plexiglass tank.

 

[bang guy]

It depends...
Electronic ballasts run the bulbs cooler (still quite warm though). As long as they are not touching the plexiglass they won't harm it. Even if they are touching it the only danger is if that area gets severly splashed after it gets hot.
With a Magnetic ballast the bulbs should be at least an inch away but that's all that's needed. Actually, if I had a Magnetic ballast I would just throw it away and buy an electronic... but that's just me LOL
A fan strategically placed to blow air over the water surface below the bulbs will eliminate most if not all the extra heat.
Guy

 

[tigershark]

Ok, I found out that I have an electronic ballast which is what I thought I had. I plan on getting a piece of plexi cut to fit over the top of my tank to keep most of the water in the tank and to keep water from splashing the bulbs. There shouldnt be too much splashing in the tank but who knows what my future fish will do. I think I'll try and get a small fan or 2 to mount on the side of the bulbs and try to cool them down a little bit that way. Thanks for your help!