Algae growth related to MH color temp?

[marclibert]

Anyone know if there is any correlation to algae growth in regards to the Kelvin temp of a MH bulb? For example a 10K bulb has more yellow/white than a 20K bulb. Would this promote more bad algae growth? I seem to get an outbreak of cyano every once in a while, I end up turning off my lights for a day or 2 to clear it out. My P04 is zero and I have pretty strong flow

[bertoni]

A 20k bulb would probably help hide green algae by emphasizing the blue. Any light with more PAR is likely to increase algal growth as well. A number of algae probably do better with lower color temperatures. I don't think it's easy to say much other than this type of generality.