Gsp coral sponge or something else?

[sabyhappy2]

Need some help on what this is on my gsp coral as it started on this one and is now on an other. A friend said it was a sponge but it didn’t come off with brushing with a soft toothbrush.‍ Is there a better way to get it off if it is a sponge the gsp is still opening fine

 

[elcapitan1993]

Kind of looks like green pipe organs, I have them and they look almost exactly like this

 

[sabyhappy2]

Kind of looks like green pipe organs, I have them and they look almost exactly like this

Any idea on if the white spots are a sponge or not or if it’s new growth or if it’s bad? My other gsp has 2 spots of it now too