Whew, thats a relief. I have all kinds of little rounds sponges in my tank. Didn't know they could look like that white stuff. I guess I have a yellow one like it in another location. I always assumed it was glue left over from the previous owner attaching something to the rock.
What kind of anemone did you get Spyral?... and what is in that picture you use with your handle?
A friend gave me a piece of rock with ten polyps on it about a month ago and I was pleased to find five new ones springing up on the rock where I placed it.
You can only see 8 of them in this pic.
In this one taken with the flash, The Clown and Damsel decided to get in the pic.