Can anyone identify this in refugium ?

[JesterOfWill]

Hi, my mother recently got into the reef hobby, and after setting up a refugium in her sump just a few days ago, she has noticed this growing from within the chaeto in the sump.
The Cheeto came from her local fish shop, and have only noticed it today so haven’t been able to get to the shop to ask if he knows.
pits difficult to see but has been circled in black in the image, can anyone tell me what this is and if it is good or bad ?

 

[FLReefer101]

Aiptasia. They are the enemy!

 

[JesterOfWill]

Aiptasia. They are the enemy!

Thank you, I was trying to find out and see if that was the case.

getting her to remove it from the sump the now.
its only been in a couple of days and a small amount, so doesn’t look like it’s manages to spread anywhere.