Something's about to hatch in my tank!

[pwreef]

These things have been getting bigger by the day. What are they? Some kind of bubble algae? I looked at a bunch of pictures, cannot find what they are. I bought this tank from someone else it was already established. This stuff only grows on one of the live rocks.

 

[Chiefmcfuz]

Looks like sponges to me

 

[smoq]

+1 They are probably white sponges, I have them too and they look similar to the ones you pictures. Sponges are generally a sign of a healthy tank.

 

[Dre]

Wait till they hatch...

 

[tenMann2]

definitely sponge, I have them as well, they do down when you push on it and puff right back up.

 

[reefer4eva]

They look like snail eggs i have them also .....nausarius snail eggs ...i think thats how you spell it

 

[NanoAquatic]

I had those and after some time, my tank was filled with tiny snails. Literally thousands of them.