Yellow Thing Growing on Rocks

[Chris L]

Hi folks,
I have some strange yellow thing growing on the rocks and can't figure out what it is. I have not introduced any new fish or corals in months. I just noticed them two days ago. They have a yellow base and have clear tubes protruding from the top. Can someone identify this? Is it friend or foe?

Thanks!

 

[Rainblood]

id guess its a yellow sponge or some sort

 

[Jikkermanccini]

Yeah just a yellow sponge. That species is super common in younger aquaria, they will balance out and dissipate after a few months. They're totally harmless since they only grow in the dark.

 

[Chris L]

Thanks for the identification. My tank and reefing experience is 18 months old. Always a bit alarming when something new pops out of the aqueous ether.

 

[gill]

Yellow sponge. Kind of cool. If you don't like it, thankfully, they grow pretty slowly and easy to pick off. Unlike the dam*% green mushrooms that I wish I'd never let into my house.

 

[billyocean]

Sponges are good mmmkay