Treatment for flatworms?

[myjohnson]

Yeah dude. They gave me a hard time in my last tank. At least it's not the red kind.

[snookfish]

Have you guys tried a six line wrasse? hopefully compatible with your other livestock. I know they are reef safe and scrappy if most other fish try and mess with them. I had flatworms in a tank years ago and my six line (which i still have) decimated the population in about 2 weeks to the point where I never saw another one again, and I still have rock from that tank. They do a good job of keeping copepods in check as well, which isn't a problem unless you have a mandarin. They're cheap too, i got mine for $14

[Darbex]

I was wondering if there was a non-chemical solution. What size tank do they need?