Identification of this strange Algae


New member
I have been battling this strange red/Crimson algae for about a month now. I have been doing weekly 30% water changes and I have decreased the intensity of my lights. I have also upped the flow and I have cut back slightly on how much I feed. This seems to have slightly slowed the spread but it doesn't look be dying back.

At first I thought it was cyano but it doesn't fit the description. It is not slimy, it just looks like coralline algae only a different color. I have attempted to scrub it off with a toothbrush but it is tough to get it off.

Let me know what you think and how to better treat it. Thanks [





Red coralline algae.

Don't bother trying to get rid of it... Anything that you do successfully will also be killing the purple stuff and any other hard corals in your tank.


New member
I've got green, purple, pink and red in my tank. Makes it look more natural with the different shades and tones.


I had a particularly invasive red coralline, but it made some cool plating patterns so I don't mind. Too much of any one color isn't ideal...