Baby Urchin?

[Jfinn]

Photos shown through 40x magnification loop. Have half-dozen of these on the glass showed up overnight. Surely this is a unique one.

 

[James M]

Medusa hydroid

 

[Wolf89]

Agreed

 

[Jfinn]

Medusa hydroid

Thank you! Now all I need to do is worry if it’s good or bad...seems mixed reviews.

 

[ScottR]

Thank you! Now all I need to do is worry if it’s good or bad...seems mixed reviews.

They are common in newer tanks and go away on their own typically. I wouldn’t worry.