Is it aiptasia or maybe hydroids?

[robbo3542]

Hello everyone,

First of all Happy New Year to everyone!
I do have a question. I noticed todays some small white polyps on one of the rocks in my tank. I was trying to take pictures but they are not the best quality. Polyps are white color and have around 4mm height. I can see they have leg and some tentacles. There is probably around hundred of them. I do see them mostly on one rock.
Tank is 6 months old (3 weeks ago I moved everything from my 20G to new 40G AIO. I used dry rock and recently i only added few snails from LFS and tang from Petco.
I am attaching picture showing polyps and my whole tank.

Link to the video: New video by Robert M
and additional photo: New item by Robert M

Let me know if you know what it is. These rocks have been in tank since the beginning. I bought them dry.

edit: I noticed same polyps on other rocks. Not as many as on this one.
Thank you in advance for your help!

 

[kharmaguru]

to me they look like aiptasia.

 

[Reefing102]

Given the size and what I can see as far as tentacle thickness (or lack thereof), it looks like colonial hydroids

 

[griss]

I’d like to see clearer pics, looking on my phone I can’t see them clearly. But, I’m thinking hydroids from what I can see.