ParaGuard - External Parasite Fish Treatment

Grouped product items
100 mL ParaGuard - External Parasite Fish Treatment

SKU: 213213

In stock


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ParaGuard is the only fish and filter safe aldehyde-based parasite control product available for the treatment of external fish parasites. 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 external parasites (e.g. ich, etc.) and external fungal/bacterial/viral lesions (e.g., fin rot). It is particularly useful as a dip when receiving new fish, or as a treatment in a hospital/quarantine tank.



  • Eradicates ectoparasites and fungal, bacterial, and  viral lesions
  • Safer to dose than formaldehyde, formalin, and methanol
  • Will not adversely effect bio-filter


Available in Six Sizes

  • 100 mL
  • 250 mL
  • 500 mL
  • 2 Liter
  • 4 Liter
  • 20 Liter


Directions for Use


Hospital Tank Dosing

  • Remove all invertebrates from the tank as well as any chemical filtration.
  • Use 5 mL (1 capful) of ParaGuard for every 40 L (10 US gallons).
  • Repeat this dose daily as required as long as fish show no stress.


As a Dip

ParaGuard is gentle enough to use prophylactically (without visible symptoms) if needed, such as when receiving a new fish, prior to addition to quarantine.

  • For 1 hour dips, use 3 mL per 4 L (1 US gallon) in a container separate from your main tank.
  • Dips may be extended if the fish show no evidence of stress.
  • Keep in mind that many diseases linger in the display tank water as well as on the fish. Giving a fish a dip treatment does no good if they go right back into infected water.


Cautions: Not recommended for reef aquaria. As an alternative, use Seachem’s MetroPlex. Some fish are more sensitive to medications than others. Eels, rays, sharks, and many others are well known for their sensitivity to all kinds of medications. If you suspect that your fish may be sensitive to medications, it is just fine to start with a partial dose and build up to the full dose over several days.

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Product Questions

Does this work for uronema on chromis as a replacement for formalin?
Question by: Andrew Robson on Aug 2, 2022, 11:03 PM
Malachite Green or Formalin would be much better options to treat uronema but Paraguard might help diminish the parasite. Once a tank is infected, running it fallow will not eliminate uronema from the system.
Answer by: Scott F. (BRS Staff) on Aug 3, 2022, 2:00 PM