My SE MH's are about 8-9" from the surface of my water and would like some help figuring out what kind of material, and how close to the MH's themselves I can put the material to protect them from water splash and to help keep some of the heat from reaching the water. I obviously do not want to filter out any of the light if possible, so it all reaches its intended targets. Thanks.

Hi jwavec,

I don't have MH so I can't answer your questions. But I would like to say
:welcome: to TR.

plexi-glass/acrylic is likely the best option. i think UG-58 is the best type to use but no the only option. anything you add will need to be cleaned and will defract "some" light, but its usually acceptable

welcome to TR...

i just put mine a lil far up. i think 9 inches and be very careful if i have to stir up the water

Rob--- What thickness? Where can a UG58 be purchased? Thanks

i believe it was 1/8" and it should be available from any hardware store..
from my reading the UG58 was a recommendation and was not really a requirement. this was from Eric Bornemans Aquarium Corals book.. it indicated that this was likely a good type. nothing was stated as being fully tested and confirmed.
worst case, just get what you can and keep it clean

i too, like iglowce, just keep mine up higher

mine are up high too. i keep them about 8"-10" of f the water surface.