dude, phosban over new bulbs, no question. MH bulbs can keep a decent ammount of lighting output for something like almost 3 years. The color will shift to your eyes, but if you never notice/care, your corals will continue to get similar ammounts of PAR. If nothing else, down the line throw $50 down and buy some used bulbs or something. I've only once used new bulbs. I used to run year old XM 10ks, then I broke them and had to buy new hamiltons because I needed bulbs in a pinch, and now I'm running 6 month old XM 10ks again. My corals only slow down because of pests, never because of light.