Good find or Bad find?

[Medicreefer]

These guys came free with some live rock I purchased. they started out as just a hard round disk with ridges. Pinkish coloring with a prominent white mouth area. after a few weeks in the tank they started extending decently long blueish green tentacles. There are about 6 in a cluster on one of the rocks. They are about the diameter of a nickle at the base and the tentacles extend about an inch. They look almost like a Duncan or a flowery anemone. They eat meaty pieces of food that I offer them by closing in around it. I like the way they look and haven't noticed them spreading anywhere else. Sorry for the blurry pic. they are kind of tough to get a good pic of. Anyone know what they could be? Also the pinkish leafy thing growing near them is new. Any thoughts on that?

Thanks!!

 

[Tahoe61]

Hidden Cup Coral (Phyllangia americana) I believe.

 

[Tahoe61]

The macro algae could be one of these
Nitophyllum
Cryptonemia Crenulata
Red Dictyota

 

[Medicreefer]

So I can keep them?

 

[Tahoe61]

Yes on the Hidden Cup.

Depends on how invasive the algae is. The piece is too small for me to make an accurate ID.