Help ID stuff on Liverock
 

so maybe im just being paranoid cuz things just seem to be going wrong for me lately.

but does anyone know what this stuff is thats growing on my liverock.... it seems to be in the crevices

http://i579.photobucket.com/albums/s...1at91804PM.png

Looks like sponge...

how did i get it? i've had this liverock for about 5 months and never had it before.

Sponges... I have those and the pineapple shaped ones in my sump (where it's dark) I also have a dark purple sponge on the live rock in my main tank. They're handy filter feeders!

pineapple sponges. they flourish under good water conditions and time. they like dark spaces and gentle flow. good for your tank. as your tank matures its likely youll see a few more critters show up.

stolen quote...

i use RO/DI water religiously. but if they're good i guess ill just leave them alone

I would just leave them alone. If you scrape them off the rock they'll just break into little bits with each little bit having the potential to settle and form a new colony somewhere. Like cale262 said, they are self limiting. Once they have nothing left to build colonies they'll start to disappear.