CrystalClear KnockOut Plus is an all-natural, fish treatment that eliminates Plus prevents external single-celled parasites or fungal infections. KnockOut Plus works extremely well with pond fish species such as koi and goldfish and unlike most fish treatments, there is no need to remove your filters before treatment. Furthermore, when used routinely, KnockOut Plus works as a strong preventative treatment. Use anytime new fish are added, during pond clean-outs, during spring start-up or any time fish are stressed. KnockOut Plus is a broad spectrum treatment for a variety of parasites including ichthyophthirius (Ick), sporozoan parasite, dinoflagellate infections as well as fungi such as saprolegnia, achlya, leptomitus and pythium. May be used with most invertebrates including snails. 1 oz will treat up to 60 gallons, apply daily for 7 days.