ID help

[prettyhappyreef]

Hello,

we got an aquacultured coral several months ago. We dipped and scrubbed it and tried to remove any pests. However we have found these structures growing on the bottom of the mount, it has spread to around the mount. They seem to be light sensitive and will get larger at night time, and shrink during the day. From what we can see they have not harmed any coral around them or any of our live stock.
While I was content to let them grow for a bit since they were not harming anything I am getting nervous now that they seem to be growing a lot. Any ideas what they could be?

 

[DaJMasta]

Colonial tunicates (sea squirts), they're filter feeders and there are a few varieties with striking color patterns like that. Neat!

 

[WheatToast]

Colonial tunicates (sea squirts), they're filter feeders and there are a few varieties with striking color patterns like that. Neat!

Dang it! You beat it to me!