With any light you need glass tops to cover the tank.
Says who? my 90 (440 watts
vho), 45 high (175 watts metal halide), and my 20 long (60 watts
pc, oddball set-up), None of these have a glass top, and I've never had a single problem. I know for sure that these bulbs have been splashed with water occasionaly, no harm done.
Sorry TG, but why do you say a glass top is required?
Glass tops get condensation and other stuff built up on them. I think this cuts down on your light, sometimes a LOT, depending on how dirty it gets. My 20 long has a 2x65
pc set up With a glass top. I have to clean the glass too often for my lazy personality! If I had that tank to do over, I'd go with 1x65, and a light designed to sit on the tank edges, not one like I currently have which is just short enough to require a glass top to sit on.
Theoretically, I like the various lights I see these days that have legs, designed to sit on the aquarium frame. I don't see me buying any new lights any time soon, or I'd give them a try.