WHat is this film?

[JON]

This appeared overnight on my live rock. What is it?

 

[gcvt]

I have some white encrusting sponges that look just like that - all that popped up in only one day??

 

[JON]

yeah, I put the rock in yesterday around 4 pm and when I got up this morning about 7 am it was there

 

[kreblak]

I looks like the bacterial sludge that forms over shrimp tossed into tanks to cycle them. That is crazy that all that appeared overnight!

 

[mogurnda]

Does it rub off easily? I'm thinking some sort of bacterial scum, but even that should take a while to develop.
Another possibility is that it was something that deflated during transport, and only became noticeable when it reinflated.

Clutching at straws...

 

[kreblak]

Can it be scraped off? Is it sticky? Can parts of it be removed while other parts seen unaffected? I am just wondering if it is one organism or if it is bacterial growth.

 

[JON]

It starting to reduce in size, and turned white. Holes are starting to appear in it. I think whatever it may be is decomposing.