Help! Red algea

[cpalm89]

I have noticed some of this red algea stuff and now there is a lot more of it. Does anyone know what it is and what causes this? or if it is harmful? Thank you

 

[pat8you]

Cyanobacteria. It's very common. It's not harmful to the tank but it can spread very quickly so you will need to start working on getting rid of it as soon as possible. Use the forum search and just type in cyanobacteria. There will be 3 dozen threads full of links on the steps to take to get rid of it.