Neon yellow coral like growing??

[Sonny bats]

Noticed these tiny coral like looking thing growing on my live rock for sometime now, can anybody tell me what it is? It was never there before..

 

[kdpuffer]

Sponges, bright and yellow like sponge bob.

 

[Sonny bats]

Really? Lol How do they grow and how big will they get? Are they something to worry about?

 

[bribo12]

They will come and go. Nothing to worry about

 

[kdpuffer]

They can come and go or they just stick around and grow. I've seen some in my tank around 2 inches