Identification needed

[mhart032]

i saw these on my live rock i have looked and looked and i cant findout what it is.. can you guys/gals help please. they are the little whit/clearish sphere looking things..
thanks

 

[Kurt_Nelson]

Sponges. Totally harmless and kinda cool to watch grow. They'll come and go throughout the tank, as nutrients increase and decrease.

 

[mhart032]

Ok, nice thank you, its been worrying me..
Matt

 

[melosu58]

I agree. I have many of those sponges in my tank. They are filter feeders so that`s a good thing.