Use in a fine mesh filter bag and add to your filter. (warning, use the finest mesh you can find; purigen is tiny and will slip through most larger filter bags.) Clean when it turns dark brown or black (it's white).
Directions from Seachem's website:
: Soak in a 1:1 bleach:water solution for 24 hours in a non-metalic container in a well ventilated area and away from children. Rinse well, then soak for 8 hours with a solution containing 2 tablespoons of Prime®
, or equivalent dechlorinator per cup of water. Rinse well. Original color and full activity should now be restored and Purigen® is ready for reuse.
How to "Recharge" Seachem Purigen