Active ingredient: Fritz Expel-P: levamisole HCl
How to use (from the label): 1 packet per 10 US gal (38 L). After 24 h do a 25% water change, removing expelled worms. Repeat one week later; repeat weekly as needed. Lights off for the first 24 h (light-sensitive). Remove carbon/chemical filtration; hospital tank recommended.
Careful: Compatible with most freshwater and saltwater fish, plants and most invertebrates, but tube worms and feather dusters may be harmed and some snails temporarily affected. May inhibit nitrifying bacteria: test ammonia/nitrite. Water may cloud during treatment.
Never mix medicines unless the label says it is safe, and remove shrimp and snails unless the label says they are safe.
Examples you may see in shops: Fritz Expel-P. Not endorsements. Always follow the label.
5 facts checked with sources