They have existed in my systems for several years and for a very brief period they reached a large population like what you've shown but now I barely notice them. I've done everything that has been recommended from flow to fish to chemical treatment and head shield slug. But if you don't QT very well (or at all) you'll just get them again... like I did. So don't do anything too crazy (like flatworm exit) unless you're really going to commit.

Mandarin Dragonets are also known to eat them but like wrasse they are hit and miss. In general any wrasse from the genus Halichoeres will sometimes eat them. The best thing you can do in my opinion is add one of these and increase your flow.

+1 on the wrasses.

flat worm exit worked for me. but my population was alot smaller than what you have. best of luck

I have had 2 for 4 months now.
One large and the other about 1/2 the largers size
Experiences vary I suppose.

Maybe chalk it up to JL having exceptional livestock.

I have had success with Myka's suggestions also.

Suck up as much as you can at water change time.

I find theat six line wrasses work quite well, 2 in a 200 gal will keep the flatworms down.

I have Blue Velvet Nudi's coming in Thursday night too. Hopefully :question:

Ken - BWA