Green Cyano or spirulina?

[Brewman1987]

Good morning,

So I have been carbon dosing for the past 4 weeks and have noticed the typical red cyano on a few spots of the rocks. Starting at about week 2, I noticed that this green matter started to form on only certain rocks. It seems to appear more during the day when lights are on and disappear during the night.

Yesterday during my water change I used a turkey baster and was able to blow off chunks of this green cyano looking stuff. I took out the rocks I could and scrubbed them with a hard brush till clean. This morning the green is back, Am I correct to assume this is cyano?

 

[Randy Holmes-Farley Verified Community Expert]

Spirulina is a type of cyanobacteria. I don't see a reason to be making a distinction any more than asking "is this animal a cow or a mammal", but in any case, I am no expert on the various species of cyanobacteria.