| Replacement H Mini Filter Cartridges, Pack of 3, 3 GM These premium cartridges help make your aquarium cleaner by removing unwanted fish waste and other debris, keeping your fish healthy and lively. Replace cartridge every 2 to 4 weeks depending on the amount of fish and number of daily feedings, simply... ... more Replacement H Mini Filter Cartridges, Pack of 3, 3 GM These premium cartridges help make your aquarium cleaner by removing unwanted fish waste and other debris, keeping your fish healthy and lively. Replace cartridge every 2 to 4 weeks depending on the amount of fish and number of daily feedings, simply... Petco.com | | $4.00 go to store |