White fungal looking growth on live rock??

[RoboPhung]

This white greyish fungal slimey stuff has been appearing on my live rock. There are small ones growing randomly all over the place. There seems to be a structure to them and they all have some kind of "hole" near the center of their structure. Can anyone help me identify it, and if it can be harmful to corals?

 

 

Any help will be greatly appreciated.

[SeaSide]

Looks like some sort of sponge. They are harmless.

[impur]

I had that same stuff when i started my tank. Is your tank cycled? If you are in the midst of the cycle they will come and go. Took about a week for mine to disappear.

[tonym]

I have them all over my rock. Like seaside said they're harmless. If anything, they're good natural filters.

[AReeferIsExpensive]

i havem...they dont get "out of control" or anything~

[KansasCoral-Nu-B]

i had a lot of those on one of my rocks.. they grew up to be shrooms.. infact i have some more on the same rock. its hard to tell of those are the same things though. but mine were translucent and had sort of a pipe coming off. the pipe grew into the cap of the shroom. pretty cool

[RoboPhung]

Yeah my tank is cycled. It's been running for 8 months and this started to appear only last month. It's not the same as the white stuff u get when first cycling your tank. It is not exactly slimey and there is that structural hole u see in the center. Like seaside said, they seem to be some encrusting sponge, not shrooms, although I wish! Yeah they're starting to appear in small forms all over my rocks. I hope it doesn't become problematic, but as of now it's fine.

[Fishguy]

I just had some of this appear on my rock after less than a week of being setup..

not cycled, at all.

 

but now I feel better..

[NoobieReefer]

Same stuff started on mine this week. ?? Anyways its been running about 2 months. Weird A

[dms12]

me 2