Is 11000k too much for a refugium?

[Nanoclowndave]

I have a 20 gal display tank and I converted my old fluval evo 5 into a sump/refugium. I’m using the light that comes with the fluval 5 gal which is said to put out 11000k. My question is, is this too much for my refugium? Right now I just have caulerpa and refugium mud in there. I’m getting a ton of algae on the glass which I contribute to having the light on While display tank lights are off which probably runs it about 12 hrs or so. Is it the spectrum or the duration?? Also, does anyone know what the spectrum of just blues on with that light and would that be a better option?

 

[Journeyman]

That's spectrum. Blue is closer to 20000k. Daylight is 6700k. 11k would be mostly white with a slight blue look. A refugium, assuming you are growing chaeto would do better in the red range.