Seachem Purigen® – 2 L
Seachem Purigen® 2 L is a premium synthetic filtration resin designed to remove organic waste and polish aquarium water to exceptional clarity. It can be used in both freshwater and saltwater aquariums and is especially useful in larger systems, fish rooms, retail aquariums, and high-bioload setups.
Unlike conventional activated carbon, Purigen® is a specialized macro-porous polymer with a strong affinity for nitrogenous organic waste. By removing these compounds before they break down, Purigen® helps reduce the organic load that would otherwise contribute to ammonia, nitrite, and nitrate.
Key Features
- Premium synthetic organic filtration resin
- 2 L / 122 in³ bulk size
- Suitable for freshwater and saltwater aquariums
- Removes soluble and insoluble organic impurities
- Helps control ammonia, nitrite, and nitrate indirectly by removing organic waste
- Polishes aquarium water for exceptional clarity
- Minimal impact on trace elements
- Changes color as it becomes exhausted
- Can be regenerated and reused
- Ideal for canister filters, media chambers, box filters, and other high-flow filtration areas
Product Information
- Brand: Seachem
- Product: Purigen®
- Size: 2 L / 122 in³
- Product Type: Synthetic organic filtration resin
- Use: Freshwater and saltwater aquariums
- Form: Loose filtration media
What Does Purigen® Do?
Purigen® is designed to remove nitrogenous organic compounds from aquarium water before they can break down into ammonia, nitrite, and nitrate.
It is particularly effective at removing:
- Dissolved organic waste
- Particulate organic impurities
- Compounds that contribute to water discoloration
- Organic material that can reduce water clarity
Purigen® does not directly remove ammonia, nitrite, or nitrate in the same way as a dedicated chemical remover. Instead, it removes organic waste before that material is converted into these compounds.
How Much Water Does 2 L Treat?
Seachem states that 250 mL treats up to 250 US gallons for up to six months.
Based on that dosage, a full 2 L container can treat up to approximately 2,000 US gallons under comparable aquarium conditions.
Actual lifespan will vary depending on:
- Fish stocking level
- Feeding
- Organic waste load
- Filter flow
- Maintenance schedule
- Overall aquarium conditions
How to Use Purigen®
Rinse before use.
Because Purigen® consists of very small resin beads, it should be placed in a fine mesh filter bag of approximately 180 microns or finer, such as Seachem The Bag™.
For best results, position Purigen® where aquarium water is forced to flow directly through the media.
Recommended Filter Placement
Purigen® can be used in:
- Canister filters
- Sumps
- Media chambers
- Hang-on-back filter media compartments
- Box filters
- High-flow areas of trickle filters
Maximum effectiveness is achieved when water passes through the Purigen® rather than flowing around the media bag.
How Do I Know When Purigen® Is Exhausted?
Fresh Purigen® has a pale, light-colored appearance.
As it adsorbs organic waste, it gradually changes to:
- Tan
- Brown
- Dark brown
- Almost black when heavily exhausted
A pronounced dark brown or black appearance indicates that the media should be regenerated or replaced.
Purigen® Regeneration
One of the major advantages of Purigen® is that it can be regenerated and reused.
Seachem's current regeneration procedure is:
- Place exhausted Purigen® in a non-metallic container.
- Soak for 24 hours in a 1:1 mixture of water and regular 8.25% sodium hypochlorite household bleach.
- Use only unscented bleach with no dyes or additives.
- Do not use splash-less bleach.
- Rinse the media thoroughly.
- Soak for 8 hours in water containing 4 tablespoons of Seachem Prime® per cup of water.
- Rinse thoroughly again.
Additional Step for Freshwater Aquariums
For freshwater use, Seachem recommends an additional 4-hour soak using:
2 tablespoons of Discus Buffer® or Neutral Regulator® per cup of water.
After regeneration, the media should return close to its original light coloration.
Important Regeneration Warning
Never return regenerated Purigen® to the aquarium if any chlorine or bleach odor remains.
If there is any doubt:
- Repeat the dechlorination soak
- Rinse thoroughly
- Test the soak water for residual chlorine before reuse
Some slime-coat products can permanently foul Purigen® and make regeneration difficult or impossible.
Purigen® vs. Activated Carbon
Purigen® and activated carbon both help improve aquarium water quality, but they work differently.
Purigen® is specifically designed to target organic nitrogenous waste and can be regenerated multiple times, while standard activated carbon is generally discarded once exhausted.
Many aquarists use Purigen® as a long-term polishing media in systems where reusable filtration is preferred.
Freshwater and Saltwater Use
Purigen® is suitable for a wide variety of aquarium systems, including:
- Freshwater community aquariums
- Planted aquariums
- Cichlid aquariums
- Goldfish aquariums
- Marine fish aquariums
- Reef aquariums
- Large display systems
- Fish rooms
- Retail aquarium systems
Why Choose the 2 L Size?
The 2 L size is especially useful for aquarists maintaining:
- Multiple aquariums
- Large freshwater displays
- Large marine systems
- Fish rooms
- Retail aquarium systems
- High-bioload aquariums
Buying Purigen® in bulk also allows the aquarist to portion the exact amount needed for each filter or aquarium.
Important Use Notes
- Rinse before use.
- Use a fine mesh filter bag of 180 microns or finer.
- Place in an area with strong water flow.
- Monitor the color of the media for exhaustion.
- Regenerate according to Seachem instructions only.
- Never use scented, dyed, or splash-less bleach for regeneration.
- Never return the media to the aquarium if chlorine odor remains.
Frequently Asked Questions
How much water does 2 L of Purigen® treat?
Based on Seachem's stated dosage of 250 mL per 250 gallons, 2 L can treat up to approximately 2,000 gallons under comparable conditions.
How long does Purigen® last?
Seachem states that 250 mL can treat up to 250 gallons for up to six months. Actual service life depends heavily on the aquarium's organic waste load.
Can Purigen® be reused?
Yes. It can be regenerated using Seachem's bleach and dechlorination procedure.
Can Purigen® be used in freshwater?
Yes. It is suitable for both freshwater and marine aquariums.
Can Purigen® be used in reef aquariums?
Yes. Seachem designs Purigen® for both freshwater and marine use.
Does Purigen® remove nitrate?
Purigen® primarily removes nitrogenous organic waste before that material breaks down into ammonia, nitrite, and nitrate. It should not be treated as a direct replacement for normal nitrate control and water changes.
Does the 2 L size come pre-bagged?
No. The 2 L size is bulk loose media and should be placed into an appropriately fine filter bag before use.
Available at Tropical Treasures Wyo
Seachem Purigen® 2 L is available at Tropical Treasures Wyo in Cheyenne, Wyoming, when in stock.
Eligible dry goods are available for shipping.
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