Digitate hydroids???

[Whitebird1]

I see 6 or so Digitate hydroids on a polop frag rock and a few on anouther rock that must have spread. I found the ID on Melvins Site. http://melevsreef.com/id/kritter1.html
Question: Is having this in my little ocean a possible problem???
Greg

 

[moose8721]

I have some of those, probably have had them as long as I've had my tank. Don't seem to be multiplying at any kind of alarming rate. I never realized what they were, thought they were some type of worm.