Hard red algae

[AdeptDeveloper]

Hi,

I seem to have this very hard red algae or maybe coralline growing on one of my rocks. It's not slimey or hairy at all. It's just hard. Can't really even scratch it off that easily.

Anyone know what it is or if I need to be concerned about it?

Thanks,
-Steve

 

[cosmo]

Looks like cyano, but must be just really red corralline, if ya can't scrape it off.

 

[AdeptDeveloper]

Hmmm. I just tried to scrape off some of the newest areas and it did come off.

 

[54seaweed]

read this might help clarify you question
http://www.aquariumadvice.com/forums/f11/what-kind-of-algae-205024.html