CRYSTAL BIO-CHEM ZORB FILTER REPLACEMENT CARTRIDGE

I recently purchase a 5 gallon aquarium for my surviving 2 pond fish. I could not keep the tank clean with the provided filter medium and of course the tank brand doesn't list replacement cartridges or what size to get them in so I guessed and they fit perfect. Only had this for a day and water looks better

These filters work great in our filter, keeps things clean and fish happy

Used for small power filter on a 5 gallon led tank