please id

[jmac]

i found this on my rock so i picked it up and it feels soft so i put it back in the water it opened up any idea what it could be?

 

[returnofsid]

Beneficial "Pineapple" sponges. Taking them out of the water can quickly kill them. But, no worries, you'll have thousands soon, especially in unlit areas of your tank, like overflows, inside the skimmer, etc.

 

[jmac]

you'll have thousands soon,

should I than try to rid it

 

[jrgilles]

nope, unless you don't like the looks. They are beneficial for water quality