Buy Purigen -

Selectively traps nitrogenous organic waste before it breaks down into ammonia, nitrites, and nitrates.

Can be safely regenerated multiple times with a household bleach and water solution, saving money over time. buy purigen

Safely ignores simple elemental compounds to keep your tank's essential chemistry intact. Selectively traps nitrogenous organic waste before it breaks

The spherical beads change from pale blonde to dark brown or black as they fill up with waste. buy purigen