Fritz Expel-P (Levamisole HCl) serves as a powerful anthelmintic (anti-worm) and immune-boosting treatment for fish. Safe for both freshwater and marine environments, Expel-P effectively targets a range of internal parasites, particularly nematodes, when administered correctly. It poses no threat to the bio-filter, aquatic plants, other invertebrates, or healthy fish. Additionally, it enhances fish immunity. This medication works against Nematodes, Roundworms, Nodular Worms, and Hookworms, and can also be utilized as a coral dip to combat flatworms and troublesome nudibranchs. Note that Expel-P is not effective against Cestodes (tapeworms) or Trematodes (flukes). Available at ReptileSupply.com for all your aquatic care needs.