Help ID strange growth on tank wall

[Fih_12]

Hi everyone,

I am totally new to this site and forums I'm general. Pretty green when it comes to aquariums.

I have had a tank without any fish for about 2 months there are 3 snails and a shrimp on there also some live rock. A few days ago I noticed a strange thing growing in the tank I have attached a picture to this thread.

They are small tubes somewhat transparent and they look like they are attached to the wall of the aquarium with suction cups. Are these things good or bad or what? Should I be doing something about them?

Thanks in advance.:wavehand:

 

[jminick2]

pineapple sponge harmless filter feeder

 

[150Ron]

+1 to harmless

 

[ericarenee]

+3 ..

There is a epidemic of These sponges lately.. I think they are Aliens from PLUTO Here to take over the world 1 Reef Aquarium at a time..