ParaGuard is the only fish and filter safe aldehyde based (10% by weight) parasite control product available. Suitable for Freshwater and Marine Aquariums Unlike highly toxic and difficult to use formalin based medications, ParaGuard™ contains no formaldehyde or methanol and will not alter pH. ParaGuard™ employs a proprietary, synergistic blend of aldehydes, malachite green, and fish protective polymers that effectively and efficiently eradicates many ectoparasites (e.g. ich, etc.) and external fungal/bacterial/viral lesions (e.g., fin rot). It is particularly useful in hospital and receiving tanks for new fish and whenever new fish are introduced to a community tank. Directions: In the aquarium, use 5 mL (1 capful) to every 40 L (10 gallons*). Repeat daily as required as long as fish show no stress. For 1 hour dips, use 3 mL per 4 L (1 gallon*). Dips may be extended if fish show no evidence of stress. Not for use in aquariums containing invertebrates. Not suitable for tanks with reef/corals.