Best light for 50-gallon refugium

[reefkeeper1]

Right now I have a 250-watt 10K Ushio SE bulb with a parabolic reflector lit 14 hours a day over a 50-gallon refugium with gracilaria, ulva and caulerpa. Would a Iwasaki work better? Will the $59 for a new bulb be worth it? I just had the extra Ushio bulb lying around so that's why I'm using the 10K right now.

 

[Triterium]

Go for the Iwasaki for sure. Not only is that a better spectrum, it will also be brighter.