Quote Originally Posted by justin-branam
i do realize i will have to clean it. i plan on doing that with my weekly water changes. lucky for me my neighbor works at a glass cutting shop. i asked him to get me some glass that would not absorb any type of UV rays or anything, and that is as clear as possible. i think he said the clearest he has is 96% (of light passing through). i figure this will be fine. Should there be anything else to add to this?

anything else i should be aware of? Thanks for the help!
The glass on SE bulbs and covering pendants on DE bulbs is designed to absorb UV light. UV is not good, it kills stuff. The near UV light wavelenght such as the 420 nm spectrum (actinic) is good. That is what is thought to promote color pigment production in corals. Its a defensive strategy of shallow water corals to prevent them from being damaged by UV light. You are basically tricking the corals into thinking they are being blasted by UV by using the light close to UV but without damaging them with actual UV light. Remember that UV light is the light that causes sunburn and skin cancer. It is what is called "ioninizing radiation" and does the same thing to corals as it does to your skin. 96% transmission is pretty good. You just need to make sure the 4% you are losing isn't at one particular wavelength that you reall need. The glass you are mentioning is probably similar to the low iron, low phosphorus glass that is used in some of the high end aquariums. It is close to the clarity you get with acrylic.