Expel-P (Levamisole HCl), is an anthelmintic (anti-worm) and immunostimulant agent. Expel-P is safe to use in freshwater and saltwater aquaria and is effective against many internal parasites, especially nematodes, when used as directed. It does not harm the bio-filter, plants, other invertebrates or uninfected fish. As an added benefit, it boosts the immune competence of fish. It is effective against Nematodes, Roundworms, Nodular Worms, and Hookworms. Can be used as a coral dip to treat for flatworms and pest nudibranchs. Expel-P does not treat Cestodes (tapeworms) or Trematodes (flukes).