Originally Posted by Tetra22
But the problem is that the glass has to have pretty much a tight seal around the lights to actualy prevent condensation. Otherwise the water will still find a way into the fixture. And glass is still a little expensive for me right now. Maybe I could find some way to use some kind of plastic or maybe install a fan.?
I wouldn't use plastic, that will just melt & sag. <You can use heat resistant thermoplastic/acrylics - polycarborate, but that is expensive & will yellow under heat after a few years. Had that on one of my house light fixtures ... basically need replacing after 3-4 years.> Glass top is quite cheap. For a 48" tank, you buy 2 24" ones & that sits on the lip of the top trim. Even tho the seal is not air tight, it actually cuts down a lot on evaporation. For about $30, it is cheap peace of mind.
<BTW, I would still make the fixture itself water-proof even with a glass top ... it prevents electrical shock.>