Paraguard product is the only insurance available to fish and filter to control parasites based on aldehyde (10% by weight). Unlike highly toxic drugs and difficult to use formalin based, Paraguard not contain formaldehyde or methanol and will not alter the pH. Paraguard prepared using a proprietary and synergistic aldehydes, malachite green, and fish protective polymers that effectively and efficiently eradicates many ectoparasites of fish (eg ich, etc..) And injuries viral, bacterial and fungal outside (eg The putrefaction of the fins). It is particularly useful in hospital aquariums and fish tanks receiving new arrivals, and when we want new fish are introduced into a communal tank. For use in freshwater aquariums or marine.