Wunder Formalin 5%

Effective for use on skin & gill Flukes and many other external Parasites. Use with CAUTION. Formalin can burn sensitive species and is HIGHLY TOXIC to all fish in overdose. Dose on day 1 and 3, Repeat if necessary. Provide good aeration during treatment, monitor fish for signs of stress and add freshwater if required. 3ml per 20L.