White stuff growing on LR

[Nick986]

My 6 day old reef tank has some white stuff growing on the live rock. Can anyone tell me if this is good or bad or what it is? Also if its bad how can I remove it?

 

[jamesbaur13]

Looks like sponges... I wouldn't be worried if that's what they are.

What I'd worry about is the red looking hairs... As a pre-emptive measure isolate that rock from others and if they continue to grow be ready to pull it. Possibly Gelidium.

 

[Anemone]

If this was uncured liverock, I'd say its bacteria, breaking down the dead/decaying stuff on the rock. If it's bacteria, you will be able to siphon it out (and you should, you don't need that much dead stuff fueling an algae bloom). If it's sponge, it won't siphon out (although you may be able to dislodge and break it off in chunks).

FWIW,
Kevin