White tube-type growths

[C_Lox]

Any idea what these white tube type growths are? They don’t seem to be alive (see video) and brush away easily. Also seems to be growing in a hole in the rock that gets basically no light.
The tank is pretty neglected at the moment with only a handful of livestock and no corals at the moment. We also haven’t added anything new in for months






View attachment 20251213_183124_D51E2C5A-8231-4B4A-9999-5CC2DDAA0D98.mov

 

[Subsea]

No idea. Use white light for picture.

 

[C_Lox]

View attachment 20251215_130456_C9C888EC-351B-47ED-A51C-FCD39CE1B482.mov



White light pics, as requested. In case I’ve not made it totally obvious by this point,
I’m not the main reefer of the house

 

[Aquadude1]

Looks like different types of sponges to me. Harmless filter feeders and a sign of a healthy aquarium.

 

[Gumbies R Us]

I second that it looks like sponges.