Flatworm Exit not working

[christyf5]

OK this is not any kind of advice, your results may vary, etc etc.

I used 7x the dosage on my tank. It was a nano tank, 7.5 gallons total. I started siphoning them out as I saw them floating around in the tank on little mucous strings, I think I let the treatment go for about 45-60 mins then did the appropriate water change, ran carbon. The normal dosage or even the 2x dosage didn't seem to kill them. I have no idea whether I had some new strain of flatworm that was immune to FW Exit or what. Anyway, they still appeared occasionally but not too many and I would just siphon them out as I saw them. Then one day I noticed they were gone. Beats the heck out of me