Is this a sponge?

[Just John]

At first I thought these were eggs, but I can't think of anything in my tank that would lay eggs like this and I have seen more appearing around the tank. I am guessing it must be a sponge.

 

[ISpeakForTheSeas]

Either sponges or colonial tunicates; I'm leaning toward colonial tunicates, but I'm not sure on that at this point.

Either way, they're harmless filter feeders that may become invasive; so I'd keep an eye them and remove them as needed.

 

[Just John]

Either sponges or colonial tunicates; I'm leaning toward colonial tunicates, but I'm not sure on that at this point.

Either way, they're harmless filter feeders that may become invasive; so I'd keep an eye them and remove them as needed.

I think you are right about the tunicates. Photos online show many of them having the same geometric hexagon, pentagon etc. shapes these do. Thanks for the help!