White coral?

[Taco]

No idea what this. Just noticed it today. New live rock in tank. Only a month old.
It's under a rock bridge I made.

 

[the_fish_man]

it is a sponge. It is good for your tank

 

[XxVooDooxX]

if there is sponge on new LR that dies off during cycle...is there a chance it will grow back?

 

[six2sevenproductions]

If it grows back it never died.