Supa Filter Carbon 500ml in the water filter is an effective way to remove contaminants and odour from the aquarium or pond water. Improves water clarity by removing contaminants. Suitable for freshwater and marine aquariums. Can be used in aquarium and pond filters. Comes in a resealable bucket to stop the Filter Carbon becoming contaminated. Directions: The use of Supa filter carbon in aquarium filtration systems is an effective way to remove contaminants such as metal ions and dyes. Determine the amount of filter carbon required by using at least 1g of carbon per litre of water and remove any dust by rinsing in fresh water. Place the required amount of carbon either in a fine mesh bag, or trap between two layers of filter wool, and place in the filter. It is advisable to replace the carbon every four weeks. As a guide: – 4.5 Litres = 1 Gallon.