Pura Amazon media is a 100 percent natural forest granulated freshwater filter media that produces black water. It releases chemical compounds that have a calming effect on fish, impacting color and boosting vitality. The effect on plants is stronger roots and stems, better nutrient uptake and more robust growth. Large surface area promotes development of microorganisms and biological filtration. Resists degradation in any filter. Releases humic and tannic acids that moderate hardness. Releases a variety of compounds that comfort and relax fish. Releases cutting a compounds that plants use to build stronger roots and stems. Plants uptake nutrients more effectively and have greater disease resistance and larger mass. A beautiful light golden color can be controlled with amount of media usage. Result is a rich golden colored water filled with natural organic compounds that sooth, revitalize, stimulate and protect the health of both tropical fish and plants. Convenient to implement. This 16-ounce Amazon media comes in 6-inch by 12-inch size 300-micron media bag.