Does it look like flatworm?
 

I noticed this today morning. The zoa doesn't seems to be irritate by it and to me, it doesn't look like flatworm but more like some kind of mucus. Still wanted to make sure :)

http://i1304.photobucket.com/albums/...1-12112431.jpg

not flatworm,
I'd say paly poop :mrgreen:

Haha. Just as I thought. My tank is under heavy feeding with cyclop-ezze, coral snow, mysis, brine and flake so it would be acceptable that it pooped from having too many snakes :P

Thanks :D