activated carbon is used in aquariu

activated carbon is used in aquariums to remove water-staining organic compounds.the source of activated carbon is important for reef keeping aquarists who want to limit phosphate inputs to the aquarium because some sources of activated carbon leach phosphate.this can be tested by simply placing several grains of a particular activated carbon into a test vial with pure water (distilled,de-ionized or reverse osmosis)and phosphate reagent from a commercially available phosphate test kit.the carbon must first absorb water and sink before the test can confirm the release of phosphate,which may take as much as 45 minutes.if the carbon leaches phosphate,a blue color appears in the test water,confirming a positive test result for phosphate.