Quote Originally Posted by alton View Post
HQI lamps require a protective lense and SE lamps do not. Coral Magazine had a great articile on this. I switched from DE to SE when my DE lamps where losing 50% at 8 months. I have had 12K Reef flux SE last up to 18 months with only 10% drop off in lighting. Some swear by them(DE) I know on my bosses tank which has Giesemen lamps they last almost 2 years. I think the trick here once again is to match the lamp to the ballast.
how did you measure the drop off, also what kind of ballast where you running the DE, magnetic, electronic?