Seachem Purigen: The reusable solution for stubborn water discoloration
Is your aquarium suffering from a persistent brown or yellow tint caused by driftwood? Or does the water remain cloudy no matter how often you perform water changes? Seachem Purigen targets the source of the problem. This macroporous synthetic polymer does not trap dirt particles but selectively removes dissolved organic waste. It binds nitrogen-containing organic compounds before they break down into ammonia, nitrite, or nitrate. As a result, the formation of ammonia, nitrite, and ultimately nitrate is significantly reduced, leaving your aquarium water crystal clear.
How it works & Capacity
Traditional filter media such as activated carbon become exhausted quickly and remove a wide range of substances indiscriminately. Purigen works differently. According to Seachem, its microscopic pore structure provides a significantly higher adsorption capacity than many conventional synthetic resins, resulting in a lower organic load in the aquarium.
Purigen removes virtually no minerals or trace elements and therefore normally has no measurable effect on GH or KH. During use, the media gradually changes color from cream to dark brown or black, making it easy to see exactly when it has become exhausted.
Photo: fresh Purigen vs. exhausted Purigen
Specifications and dosage
Each 250 ml of Purigen treats up to 1,000 liters (approximately 265 US gallons) of aquarium water. Depending on the organic load, one filling typically lasts several months. Always use the media in a fine mesh filter bag with a maximum mesh size of 180 microns. Position the bag in an area with maximum water flow, such as directly inside your filter media chamber.
Step-by-step regeneration
Do not discard Purigen once it has turned black. The media can be regenerated repeatedly using household bleach:
- 1. Soak: Soak the Purigen for 24 hours in a plastic container with a 1:1 solution of water and regular, unscented household bleach (8.25%). Perform this step in a well-ventilated area.
- 2. Rinse: Thoroughly rinse the media under clean, cold running water.
- 3. Neutralize: Soak the Purigen for 8 hours in water containing 2 tablespoons of Seachem Prime per 250 ml of water. This removes any remaining chlorine.
- 4. Buffer (freshwater only): Soak the media for 4 hours in a pH buffer solution, such as Seachem Neutral Regulator, to stabilize the pH.
- 5. Check: Smell the media. If any chlorine odor remains, repeat the neutralization step with Seachem Prime. Only return the media to your filter once the chlorine smell has completely disappeared.
Safe regeneration: Not every water conditioner is compatible with Purigen. Some products contain ingredients that can permanently bind to the media. If Purigen is later regenerated with chlorine bleach, these substances may form harmful chlorine compounds that are dangerous to fish and other aquarium inhabitants. Always follow Seachem's recommended regeneration method. Neutralize bleach residue with Seachem Prime or Seachem Safe and avoid using alternative water conditioners during the regeneration process. If you are unsure whether a product is suitable, do not regenerate the Purigen until you have confirmed its compatibility.
Our tips:
- Using Purigen in a nano aquarium or shrimp tank with a small external filter? Choose the ready-to-use 100 ml version. It comes factory-sealed in the correct fine mesh bag. Loose resin beads are extremely difficult to remove from the substrate if they escape.
- Store unused Purigen slightly moist in a sealed container. This keeps the media easy to handle and prevents the beads from sticking together.
- If you own two portions of Purigen, you will always have one clean batch ready to use while the other is being regenerated.
