Seachem Purigen

250 mL

$54.95

Cost per litre treated

5.5c

Water type

Freshwater + Marine

Media type

Synthetic adsorbent resin

Media volume

250 mL

Lasts

Up to 6 months

Seachem Purigen

$54.95

100 mL 250 mL 500 mL 1 L 2 L 4 L

A resin that polishes water clear by capturing organics before they become nitrate. Seachem Purigen is a synthetic adsorbent, not a carbon – it removes dissolved and colloidal organics directly, rather than waiting for them to break down into ammonia and nitrate first. Run it in a media bag or reactor and it noticeably improves clarity within a day. It's regenerable with a bleach soak, so the same batch can be reused rather than thrown away when it's exhausted.

Key features

Removes organics at the source – captures dissolved and colloidal waste before it's broken down into ammonia, nitrite and nitrate.
Visibly polishes water – noticeably clearer water within 24 hours of use in most tanks.
Regenerable – a 1:1 household bleach and water soak restores it to original colour and activity, so one batch can be reused repeatedly.
Colour-change exhaustion indicator – beads darken from their original colour to brown or black as they exhaust.
Fresh and marine safe.

Specifications

Brand	Seachem
Media type	Synthetic adsorbent resin (organic scavenger, not activated carbon)
Dosage	1 mL Purigen per 4 L of aquarium water
Water type	Freshwater and marine
Regenerable	Yes – 1:1 household bleach:water soak
Rinse before use	Yes
Recommended bag	Fine mesh, 180 micron or less
Sizes available	100 mL, 250 mL, 500 mL, 1 L, 2 L, 4 L

Which size do I need?

Purigen's dosage scales with tank volume, at 1 mL per 4 L. The 250 mL size is the sweet spot per litre of water treated – it works out cheaper than both the 100 mL bottle below it and the 4 L above it, so buying bigger isn't automatically better value with Purigen the way it is with Prime or Pristine.

Size	Water volume serviced	Cost per litre serviced
100 mL	400 L	9c per litre
250 mL	1,000 L	5c per litre
500 mL	2,000 L	5c per litre
1 L	4,000 L	5c per litre
2 L	8,000 L	4c per litre
4 L	16,000 L	4c per litre

These figures are the cost to service that volume once, before regeneration. Because Purigen can be regenerated with bleach and reused rather than replaced, the real cost per litre over the media's working life is considerably lower than the table above.

Care and maintenance

Rinse before first use.
Run in a fine mesh bag (180 micron or less) inside a filter, reactor or sump – not loose in a filter basket.
Watch for the colour change from its original colour to brown or black as the sign it needs regenerating or replacing.
To regenerate: soak 24 hours in a 1:1 solution of regular unscented household bleach and water, in a non-metallic container, in a well-ventilated area away from children. Rinse well, then soak 8 hours in a dechlorinator solution (4 tablespoons of Seachem Prime, or equivalent, per cup of water) and rinse well again. For freshwater tanks, an optional 4-hour soak in a buffer solution follows. Do not reuse if any bleach or chlorine odour remains – test for residual chlorine if unsure.

Suitable for, and not suitable for

Suitable for: freshwater and marine aquariums wanting clearer water and lower organic load, run alongside normal biological and mechanical filtration.
Not suitable for: biological filtration on its own – Purigen removes organics, it doesn't replace a biofilter or nitrifying bacteria.

Warranty and delivery

Covered by your rights under Australian Consumer Law in addition to any manufacturer terms. Standard parcel freight.

Common questions

Is Purigen the same as activated carbon?

No – it's a synthetic adsorbent resin that targets dissolved and colloidal organics directly, rather than carbon's broader adsorption. Many aquarists run both, in separate bags.