What is this ? Cyano ?

[AToMiC]

Hey all, we are new to reefing and have had our tank setup for a Cpl months and its been really good. except this dark red/purple looking covering on some of our rock, its not slimy no hairs on it. we tried to scrub it off with a brush with no luck. we have taken several water samples to the lfs and they said the water is great. any thoughts?

 

[i cant think]

Hey all, we are new to reefing and have had our tank setup for a Cpl months and its been really good. except this dark red/purple looking covering on some of our rock, its not slimy no hairs on it. we tried to scrub it off with a brush with no luck. we have taken several water samples to the lfs and they said the water is great. any thoughts?

It doesn’t seem like cyano, with cyano it usually comes off the rock so I’d say it’s maybe coralline

 

[AToMiC]

It doesn’t seem like cyano, with cyano it usually comes off the rock so I’d say it’s maybe coralline

I Just googled some images of coralline and you could be right

 

[Little c big D]

looks like coraline! That's some nice growth also. It came on slowly?

 

[AToMiC]

looks like coraline! That's some nice growth also. It came on slowly?

Yes it has been a slow growth, as we monitor and age the new setup it has been growing. was just concerned it was something worse that we needed to take care of before adding more live stock and corals

 

[Little c big D]

Yes it has been a slow growth, as we monitor and age the new setup it has been growing. was just concerned it was something worse that we needed to take care of before adding more live stock and corals

Congrats, that's a good sign!

 

[ReefGeezer]

I have the same thing or at least something similar going on in my fairly young tank. It really doesn't look crusty like coralline, but is tough as heck. It won't come off of rocks with a brush and gives doesn't scrape off of plastic surfaces easily. Grows in lighted areas and spreads fairly slowly. While I suppose it could be red turf algae, I think it is a sponge. I'm going to try two remedies: reducing silicates by running GFO for a while; and adding a couple of Urchins.