Polyps in the sump and tank

[servus]

These things grow inside the sump (about 20 of them) and in the tank (I can see two) where the water is more stagnant, in a corner. Not sure what they are, if they are bad or not and/if I can/should remove them. I would appreciate some advice. The tank is 8 months old, 75g, parameters normal. They're 1/4 to 1 inch long, about 1/16 diameter.

 

[BranchingHammer]

Look like harmless sponges. Good filter feeders!

 

[dhanking]

Sponges or tunicates. They’ll clean up your water and when they die you can remove them from the tank so they don’t create an ammonia spike.