Running PFO 400 duel ballest non-HQI,bulbs last 8-10 months vs. 6 months on HQI, with the HQI I would get a higher par rating but shorter bulb life. I'll have to look for the reefcentral link regarding the par rating, it shows bulb & ballast combos and their outputs, electronic,magnetic and hqi. I think this is it.... http://www.reeflightinginfo.arvixe.com/index.htm I hope this helps. I am totally happy with my lamps, I don't think my sand is too blue or anything and I appear to be having some good growth rate. My colors look good too... IMO.