Hello scottcc5s,

The two specs that are given for all HPS bulbs are very misleading; intial lumens and bulb life.

Inital lumens means just that. When you first fire up that bulb that is what you should expect. But it drops off quickly from there and most HPS bulbs after abt 1,500 hrs have lost at least 10% of that rating. That is far short of the bulb life given, usually 16,000-24,000 hrours depending on mfg and wattage.

This always sets off the debate of expensive enhanced spectrum bulbs versus cheap genetic bulbs. While the more expensive bulbs might have a better PAR value and slightly longer usefull life, people who pay $100+ per bulb are less likely to change them often enough.

OM