Sponge maybe?

[Campfiregirl]

Our Acan has a friend growing around it, we think it's a sponge. We have manually removed it twice now and it keeps growing back. Has anyone had any success in getting rid of it? If so, what process did you use?

Here is a couple of pictures of the Acan with the issue.
Plus a pic of a very cute goby!

 

[Jseimo]

Sponge for sure. They are beneficial to your tank as filter feeders but I understand the coral encroach. 2 things to try to rid them. Kalk paste/aptasia x. Hydrogen peroxide

 

[Darren in Tacoma]

Because you included a pic of a very cute goby I will personally go to your house and get rid of the sponge!

 

[Campfiregirl]

Because you included a pic of a very cute goby I will personally go to your house and get rid of the sponge!

You only say that because you live here lol!!!