NT Labs Koi Care Formaldehyde 30% is effective against protozoan parasites and flukes. Use this when fish show symptoms of a parasitic infection, including white spots along the fins and body, flicking and rubbing, gasping at the surface, or an opaque film over the body.
Formaldehyde is highly effective at treating parasites due to its ability to penetrate through the mucus layer, reaching those parasites which would otherwise be protected from alternative bath treatments. It can also be used in conjunction with Malachite to treat protozoan parasites more effectively.
Caution: Formaldehyde is a hazardous chemical and should be handled with great care, please read the warnings on the label carefully.