Overview
Seachem ParaGuard is the only fish and filter safe aldehyde based (10% by weight) parasite control product available. 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 on fish (e.g. ich, etc.) and external fungal/bacterial (e.g., fin rot). It is particularly useful in receiving tanks for new fish and whenever new fish are introduced to a community tank.
Seachem gear is commonly used for freshwater planted tanks, nano aquascapes, and routine maintenance — always match capacity to your tank volume and livestock.
Key features
- For freshwater & saltwater aquariums
- Fish & filter safe parasite control
- Seachem DOES NOT guarantee this product is safe for invertebrates and plants
- Use one capful for every 10 gallons. Repeat daily as required as long as fish show no stress. The entire 500 ml bottle will treat 1,000 gallons.
What to know before buying
- Confirm tank size, flow rate, or dosage matches your setup (check the manufacturer listing on Amazon).
- Compare the latest Amazon price with local shops — affiliate links do not change what you pay.
- Read recent buyer reviews for packaging, noise level, and long-term reliability.
Who this is for
Ideal if you run a planted freshwater tank or aquascape and want a proven seachem product with wide availability in the US and international Amazon marketplaces.


![Seachem ParaGuard, 2 Liter [Misc.] - Aqua Plants Hub](https://aquaplantshub.s3.ap-southeast-1.amazonaws.com/wp-content/uploads/2026/06/seachem-paraguard-2-liter-misc-507x1024.jpg)