Huge flat worm issue

[Scythanith]

Dose again, this time 2-3x the recommended amount. I'm not kidding. Have a large (50%) water change & fresh carbon ready to go.

I spent a week or two (like Freeze) pre-siphoning out anything I could see. I used airline tubing attached to the feeding probe. Sometimes I'd squirt a little water out of the feeding probe the loosen the nudi's off of the rock. Once you're happy with a couple weeks worth of back breaking siphoning... dose the crap out of the tank. The nudibranchs can become immune to lower doses, and all you'd be doing is ensuring the strongest survive if you dose at the same levels again. Follow the directions closely (aside from dose concentration) and wait until you see them coming off of the rocks. At that point I activated the carbon reactor, started netting them out of the water column with a fine mesh net, and siphoned them out of the nooks & crannies in the rock. I also took a powerhead and aimed it into the rocks to get out the remaining flatworms. Once you're happy with your work do the water change.

Best of luck.