Antiparasitic
De-Los
Wide-spectrum antiparasitic for gill flukes, fish lice, anchor worms, leeches, and parasitic eggs. Safe with freshwater plants at label dose.
Pack sizes
1 oz · 5 oz · 1 lb · 5 lb · bulk
De-Los is the workhorse antiparasitic in the National Fish Pharmaceuticals catalog. It targets the chitinous structures of arthropod parasites and disrupts the egg stage that most single-treatment medications miss.
Dosage and administration
Standard dose: 1 g per 60 gallons (≈225 L). Treat once, water-change 25% after 48 hours, then re-treat at half dose on day 7 to catch newly hatched parasites. Do not use with scaleless fish at full dose.
Active ingredients
Diflubenzuron, with proprietary stabilising adjuvants.
Warnings & precautions
Half-dose for scaleless fish (catfish, loaches, eels). Remove activated carbon during treatment. Toxic to crustaceans — never use in invertebrate tanks.