Add this Perfect-a-Flo carbon filter cartridge to your Perfect-a-Flo or Undertow Undergravel filter and the clarity and cleanliness of your aquarium water will astound you! Filled with activated carbon, these cartridges remove harmful gases, odors, and discoloration from your aquarium. The cartridges can even be refilled with carbon, or an ammonia remover of your choice.
Rinse in tap water before installing. Refill every two-to-four weeks, or as needed.
For Perfect-a-Flow and Undertow undergravel filters
Package of 2 cartridges.