Metal halide splash guard/UV filter question
 

Cheers! I've just received my MH retrofit kit and am trying to figure out how to place my splash guard and what size UV shielded glass I might need. I guess the first question is up to my ingenuity, but I was hoping for some help on the second.

Actually, let me revise my question a bit: how thick should the glass be? And a new question: how far should it be away from the bulbs?

I'm running 250W MH over a 120 (4' x 2' x 2') gallon tank, if it matters.

Thanks!

Andy

I'm not sure I fully understand, but I can tell you that I have a 2 X 250-watt fixture made by a reliable manyufacturer, and there's a strip of (I believe it's called "Lexite" under the bulbs by about three inches, which encloses the bottom of the fixture. I have a glass covering the top of the tank (to keep jumpers from getting out of the tank) under there by about another 2 1/2 to 3 inches because the fixture is elevated by mounts. The glass that covers the tank is 3/8".

If your bulbs are SE, there's no need to run a UV filter - they have them built in. Only double ended bulbs need filters, and for the most part, reflectors or pendants designed to hold them have the filter built in.

If you don't need one, I'd leave it out. It'll just get covered in salt creep and reduce your light output. Plus, it'll trap in extra heat.

Thanks Avi. Three inches under the bulbs is what I'll aim for, then. At three inches, I ought to be able to aim a fan between the guard and the bulb, too.

I'm not only trying to block the UV (although my eyes hurt when I stare at tanks for a long time that have exposed pendents, so I know I need more than just a bare bulb). I'm also trying to place a splash guard and avoid the light shattering if it gets hit with any water (it happened to a guy I know). But thanks for your reply der_wille_zur_mact.