Cyano and sunlight

rugby74

New member
Does sunlight cause or increase cyano algae? I have a tank that gets maybe an hour of sun during the day and my tank has cyano bad. I didn't know if the sun will increase the amount or if it causes it. I had a nitrate spike but it's been under control for a while.
 

Randy Holmes-Farley

Reef Chemist
Premium Member
Assuming it substantially brightens the lighting, it would probably boost many photosynthetic organisms, including cyano. But I would not assume the cyano is caused by the sun (that is, will go away if you block the sun). Most people with cyano do not have direct sun, and it is very common.
 

rugby74

New member
Thanks, I did have problems with nitrates but I thought the extra light was making it worse. I have a TDS meter coming this week to check my RO setup. I think that may be part of my problem.
 

ANGRY JOHN

New member
IMO the light provides nothing that normal tank light does not. The sunlight is not the source of the problem, the nutrients in the tank are. Sunlight just makes the problem worse.
 
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