The thing about flatworms is that they don't stay put. If you see some on a coral in a LFS
, then most likely they're on other corals too. There's a LFS
near me that has a tank full of beautiful zoanthids, but the tank is FULL of flatworms. They're getting a handle on it, but still... no thanks.
Flatworms are the one thing that has made me think twice about possibly doing a preventative dip (iodine) on incoming corals. But for the most part, the LFSs I frequent keep really really clean/healthy tanks so I haven't done it yet.
Looking over corals reaaaallllly good before buying for any type of hitchiker is really good. I've passed over beautiful looking corals that I've really really wanted because I didn't like the look of some of the macro algae hanging off the rock. Granted, I can pluck the algae off before putting it in the tank, but I've learned you can never get it all off. The more I get into this hobby, the more protective I'm finding I get when it comes to putting new things in the tank.