Waterlife Sterazin Treats Gill and Body Flukes & Parasite Cure 100ml BottleTreats gill and body flukes which cause fish to flick and scrape. Other symptons include 'clubbed' gills , cloudy patches on fins/body, 'yawning' and lethargy. Also treats internal worms.For use in seawater, tropical freshwater and coldwater aquaria.Do not use in aquariums containing crustaceans, echinoderms, rays, seawater sharks, piranha, sturgeon, sterlets or related species. (With these species, use Waterlife's Paragon)100ml / 5 day course for 200 litres