Dark purple algae with small air bubbles!

[csfreeman2]

What causes this and what can I do to eliminate it? Yeah it vanishes at night and the bubbles lift but what the root issue? I feed about every other day; lights run app 10hrs. Levels are good.

 

[1fishjones]

Green Emerald crabs will eat it up.

 

[Salty1962]

A picture would go a long way for us to help:)

 

[AdamNC]

Cyano, only thing you can do is feed less and export more by means of water changes and skimming.

 

[Laker32]

I had a similiar issue last month and the cause was my Kessil turned up too high. I lowered the intensity and my tanks back to normal. Cut your lights down to about 8hrs a day.

 

[twilliard]

Cutting lighting down won't help if it is cyanobacteria
It does sound like cyanobacteria
I am currently working on this here
https://www.reef2reef.com/threads/back-at-it-peroxide-vrs-cyanobacteria.241002/

Also if you would like more info on cyanobacteria here is a link for you
https://en.m.wikipedia.org/wiki/Cyanobacteria