What is this?

[mwbeach]

This reddish slightly hairy stuff just started showing up. Any help identifying and how to get rid of would be appreciated.

 

[Subsea]

Is it slimy to the touch and does it blow off easily? Does it disappear at night to come back when lights are on?

Consider cynobacteria. It thrives with o nitrogen & o phosphate in water column. It scavenges nutrients by changing chemistry under the mat.

 

[mwbeach]

It blows off real easy. Haven’t touched it. Not sure if it goes away.

 

[lapin]

Suck that cyano out each water change and suck some out inbetween changes