purple algae

[George Steinberger]

is this bad

 

[Brian barranco]

Cyanobacteria .

 

[lapin]

The red is cyano. Lack of flow in that spot is one of the main causes. You can vac it out and point a power head at that spot and it should go away over time.
Its not really bad.

 

[George Steinberger]

The red is cyano. Lack of flow in that spot is one of the main causes. You can vac it out and point a power head at that spot and it should go away over time.
Its not really bad.

thanks very much