What kind of sponges are these

[Mgex]

i have been watching them grow for a few monthes i kinda liked them at first but now they are spreading too far

 

[andrewey]

I think some people call them spaghetti sponges. I can't tell you the species, beyond saying they're probably some type of Syconoid sponge.

 

[Mgex]

I think some people call them spaghetti sponges. I can't tell you the species, beyond saying they're probably some type of Syconoid sponge.

Do they do anything bad or are just an eyesore ?

 

[andrewey]

Nothing wrong with them- they actually used to be thought of as a mark of "good water quality". In truth, they grow well when the tank is stable and there is a lot of food in the water- they're fantastic filter feeders! You can keep them where they are or if you don't like them, I would suggest relocating them to your sump or behind/underneath your live rock. If you are able to, they're certainly something that's helpful to keep in the tank.