Black algae and T5 LIGHTING

[markc]

:?: A friend has a major problem with Black algae water tests seem Ok phosphate was high up has since come down .
He now thinks that it could be due to lighting, T5s 4x39watts,2x54watts and 2 actinics lights on 9hrs.
Any ideas?

 

[Len]

I wouldn't be a bit surprised if lighting was responsible. I'm assuming black algae is referring to some sort of cyanobacteria, and my experiences are that different spectrums and intensities can have significant effects on cyano growth. I knew that it was time to change my former Ushios when cyano population increased.

Other then lighting issues, jjust maintain nutrients down via any combination of water changes, RO water, skimmer, DSB, macroalgae, and/or carbon. Cyano is quite resourceful, but low nutrients will effectively impede their growth.