Wierd white growth on Zoa

[Quickster118]

I picked up this rock from a friend of mine and as of a week ago i started noticing this one polyp as turned white and looks swollen. Today i saw to more on the other end of the rock that looked like they were started to do the same thing. Anyone have any ideas as to what would be causing this? I dont wanna lose the rest of my colony

i couldnt get a decent closeup pic (anyone know how to take pics from photoshop and put them on photobucket?) Thanks! Dan

 

[Crib]

that is pretty white,
take a look at this site.
http://www.zoaid.com/index.php?module=Gallery2&g2_itemId=761

 

[JayM]

Is an asterina star in the middle of your colony?

 

[Quickster118]

yea i checked the zoapox out and i dont think thats whats causing this but im not sure i am gonna squirt a jet of water at the colony wiht a turkey baster to see if there is anything lying within the colony that could be affecting it. thanks for the responses!