STN on an acro at the base....

[karlitosway]

I had a couple of colonies that looked just like the pic. Mine turned out to be Acro Flat Worms. I would choose a sacrificial lamb (the coral that is the most expendable with STN) and give it a fresh water dip in a glass and shake. Look for them on the bottom of the glass.

I might be wrong, but that picture looks like it could have been taken of a coral from my tank (months ago).

 

[tacocat]

If you have aggressive feeding fish like wrasses, you can blast your corals with water from a turkey baster. Acroflatties won't be able to hold on. The wrasse will eat them out of the water column if they stay suspended.

It's not a remedy, just an easy way to check. Although I did eliminate what few I had by doing this. My leopard wrasse and solar wrasse are very aggressive hunters, and they follow my hand around the tank. So I blasted the suspected corals with my turkey baster from every direction. The wrasses ate the flatties suspended in the water column. After a few weeks, I couldn't find anymore.

 

[Kent E]

same as taco cat. They may come back but I'm not as worried now that I know how to identify them.