How far above should my MH lights be above the water?

A friend of mine is telling me a foot or more but I don't think it's that much.

what kind of mh lights do you have, hqi or the old mogal style that screws in? if you have hqi bulbs you should be fine running right on top of your tank you want the most penetration as possible with sps and lps and it wont hurt soft corals like colts.  but mushrooms on the other hand id put under with caution they might spill there innards with direct light but they could always be put in the darker end of the tank. i work at a local aqurium shop we actually run everything under mh exept shrooms, leathers,zoo's and our refugium everything thats not under mh is under power compacts and a couple vho florecent bulbs in our clarity system. hope that helped you out a little

Thanks chrisg89, it was helpful. I have the mofal style setup if that helps. Currently have the lights 3 inches above the water level. Just wondering if I should move them up to reduce heat buildup over the summer months.

yea probally they might be a foot above the tank then

MrMax:

Thanks chrisg89, it was helpful. I have the mofal style setup if that helps. Currently have the lights 3 inches above the water level. Just wondering if I should move them up to reduce heat buildup over the summer months.

Moving them higher won't hurt and it will reduce the heat if that turns out to be a problem.