What is this growth

[Salty BC]

This tank is about 6 weeks old. Trying to identify the clearest white growth on the rock in this picture.

 

[shakacuz]

likely a sponge.

@ISpeakForTheSeas any idea? haven't seen any that have tube-like growth like that

 

[BryanM]

Gulf live rock? Whoever it came from you can also ask the vendor, they're pretty good about knowing whats generally on their rocks.

 

[ISpeakForTheSeas]

likely a sponge.

@ISpeakForTheSeas any idea? haven't seen any that have tube-like growth like that

The tubes are definitely sponges - the clearest part might be sponge, but it's (understandably) tough to say for sure from the picture. It could also be a mucus cocoon or bacterial film, but if it's consistently there over multiple days and not being torn by the flow in the tank, then I wouldn't expect that to be the case.