what is this? what has caused it? and how do I get rid?

[Chris Walker]

As the title says really. I have this growing in a few places and want it gone! I have co2 does Ei, use ro with seachem equilibrium.

Any help would be appreciated

 

[Mark Green]

Try this link......

Looks like staghorn, usually poor co2/water circulation

James' Planted Tank - Algae Guide

 

[Ady34]

Yep definitely staghorn algae.
Increased co2 availability, extra filter cleaning and extra water changes until it's gone, plus liquid carbon dosing (if an option) for fast effective irradication. Clean tank with good co2 will keep you staghorn free
Cheerio,
Ady.

 

[Chris Walker]

Thanks guys, co2 going up and water change in the morning!