Red Gonipora and white base

[hsingh]

Hi there,
I have a red Goni and have noticed that there seems to be a white base growing under it. Initially I had read that this is how the Goni propagates but just wanted a second opinion. The white base is hard so not a sponge. Please see attached pictures.
I took the photo at night when the Goni is receded. Just cannot find the article that said that the white base is ok?

Thanks

 

[Auquanut]

Hard to tell from the picture, but sure looks like sponge. You say it's hard. Is it crumbly, or more solid like rock? Not that familliar with gonies. Sorry.