Help with identifying white stuff on rocks

thefeds · Nov 12, 2025

I have some white stuff growing on my rock and I think it might be a worm or something. My zoa's seem to be suffering from it. Does anyone know what it is and is it harmful? I have been planning on ordering a Nano box of rocks from Tampa Bay and pulling this rock out, but I am not sure yet.

IMG_5314 - this is a video

JTP424 · Nov 12, 2025

Looks like some type of sponge?
Give it a poke and see if it's squishy.

thefeds said:
I have some white stuff growing on my rock and I think it might be a worm or something. My zoa's seem to be suffering from it. Does anyone know what it is and is it harmful? I have been planning on ordering a Nano box of rocks from Tampa Bay and pulling this rock out, but I am not sure yet.

IMG_5314 - this is a video

AlyciaMarie · Nov 12, 2025

JTP424 said:
Looks like some type of sponge?
Give it a poke and see if it's squishy.

I thought the same thing. Looks very similar to a sponge a delt with early in my tanks jounrey. '

OP, does it blow off the rocks at all? You can use a turkey baster to see.

thefeds · Nov 12, 2025

It does not blow off

thefeds · Nov 12, 2025

sorry, was in the middle of water change when I replied above. It does not blow off and when poked it just seems do nothing. After water change it is still all there.

I do also see what looks like white tubes coming out from some of the whitish sections.