Alveopora pink sponge - Not sure what to think about this (photo)

[Aqua Splendor]

I have this Alvaeopora and it look like a pink sponge, I have the same thing in another tank that grow on my rack filter (no light)

What do you guys think?

 

[Aqua Splendor]

I tried with little brush/tooth style, some water pressure, it doesn't go away, could it be possible it's the natural tissue of the coral (I doubt)
(Air doesn't work)