Help ID this microalgae

I searched the forum and read the ultimate guide as well as many google searches, couldn't find this type of algae.

It looks like little brown puffs each having their own individual stalk. It is only on this one rock.

Thanks for the help

 

Those might be Colonial Hydroids, not a good thing. :-(

 

+1 You need to get rid of them before they spread.

 

i've had them for 10 years /shrug

 

Ok removed the rock and the one under it because it had started to spread. It is only on about 10 lbs of rock so I am going to just remove the rock and let it turn to base rock again i guess.

I read that boiling water/lime juice/fire/kalk paste will help kill them off but is it worth the risk for 10 lbs of rock?

 

Not really IMO

 

Any idea where this could come from? I used dry base rock and some rock from other people's tanks. No mention of the pests and they just kind of sprung up out of no where 2 months after adding to the tank.

 

Could have been in the rock you got from others and just started to grow because of newly available nutrients in your tank.

Also, did you recently add any corals?

 

probably came in on a piece of coral that you got, Probably didnt see it and it just grew out in your tank. Definately want to get rid of it, can and will sting corals and spread

I have a NO CALUPRA policy in my tanks, esp my SPS tank. Today I found a large piece attached to my powerhead,,,,,,,must have come in on a frag and very upset by it!

 

These sprung up before I added a coral to the system. Must have always been on the rock and just didn't have the nutrients to grow.