Poly Filter

We have been using this product for many many years. While we don't know exactly how it works, we do know that it works great with no adverse effects on aquarium fish. It is a staple product in all of our marine aquariums. It works in power filters (including Penguins, Whisper, and AquaClear filters), undergravel filters, canister filters. The filter removes harmful organics, toxic ammonia, heavy metals, all forms of phosphates, and medications after treatment. The Poly Filter will not soften the water or remove trace minerals. It is excellent for medication removal and, therefore, should be removed before any medication is added to the tank. It has a unique color change that shows the removal of specific pollutants. Turns color as it absorbs harmful organics, progressing from white to green and then to black. It will turn blue when removing copper, red when removing iron, and green when removing ammonia. This filter adds nothing to the water. It can be cut into any size or shape. Flexible enough to be rolled. Extends the time between water changes. For freshwater and marine aquariums. Approximately 4" x 8".