Small jellyfish and hydroids/polyps

[ReefJCB]

I moved all of my corals and fish to new rockwork that I had cycled in brute cans about 4 months ago.

I’m seeing these polyps that I’ve assumed are hydroids in shaded areas of the tank. I’d never seen them on my old set up.

Just recently I’ve noticed small jellys. After a breif search I’m thinking they are maybe Cassiopeia jellies in their polyp stage. Any ideas on ID, and what I can do to get rid of them?

 

[Gvirgoan]

Had these pop up out of nowhere, started to disappear when I added more flow

 

[mikimoto01]

any update on what these are? I have them too

 

[Gvirgoan]

They’re hydroids and they seem to come and go. So far for the past 2 years my livestock has been fine with them but wish I found something to get rid of them

any update on what these are? I have them to