I read multiple threads on various refugium lighting options... Several folks referred to the PAR38 LED bulbs available at Lowe's and Home Depot. I had used a simple clamp on and CFL before and it worked fine... but decided to give the PAR38 LED's a go... Quick question... what Kelvin rating... I saw some at 2700 and some at 5000K.... I could see logic in both directions.... 2700... more to the red spectrum for growing algae... 5000... closer to daylight and higher energy wavelength for penetrating water depth. Since my fuge is a 55 gallon tank, I chose the 5000K.... Thoughts??? THe threads I read just said "PAR38 LED's".... they did not specify which temperature rating they were talking about. M PS -- BTW... I got two PAR38 5000K bulbs for my 55 gallon... I figure that'll be plenty... I can add more later if needed.