Help ID, Aiptasia, Feather Duster, Hydroids, or Clove Polyps

[HiBRiD109]

13.5g tank is about 2 months old. Just noticed them yesterday after water change. I initially thought were aiptasia but not sure. They are only on this toadstool frag rock I got 1 month ago. The reason I don't think they are aiptasia, at least the common ones, is all the pictures I've seen of aiptasia, have long smooth tentacles. These have tentacles with branches like a feather worm or Clove polyp. They are brown/tan in color. I haven't messed with them. There's about 7-8 that I can see. Only on this rock that the toadstool came on.

 

[Crabs McJones]

I'm afraid those are in fact aiptasia

 

[HiBRiD109]

I'm afraid those are in fact aiptasia

I was afraid so. I think I am just in denial. Would the best way is to try to remove said rock and spray each one with lime juice? They're too small to poke. Maybe hold the coral and dip the rock in pure lime juice for 30-60 seconds, then dip in RO a few time, then dip in separate bowl of tank water and let sit for a bit before adding it back to the tank?

 

[Crabs McJones]

I was afraid so. I think I am just in denial. Would the best way is to try to remove said rock and spray each one with lime juice? They're too small to poke. Maybe hold the coral and dip the rock in pure lime juice for 30-60 seconds, then dip in RO a few time, then dip in separate bowl of tank water and let sit for a bit before adding it back to the tank?

Lime juice on the outside of the aiptasia doesnt really do much. Best bet would be to pull the rock, scrape as much off as possible and superglue over the spot where they were so they cannot grow back. Another option would be to get a natural predator such as a filefish or copper and butterfly if your tank size and other fish allow for it. Or peppermint shrimp have been known to eat them