CaribSea’s Eco-Complete Planted Aquarium Substrate is mineralogically complete! It contains iron, calcium, magnesium, potassium, sulfur, and over 25 other elements to nourish your aquatic plants. Eco-Complete Planted Aquarium Substrate contains all the mineral nutrients needed for luxuriant aquatic plant growth without nuisance algae. Iron rich Eco-Complete eliminates the need for laterite. Nitrate and carbonate free, it will not increase pH or carbonate hardness in the long term. No artificial dyes, paints, or chemical coatings. Eco-Complete contains live Heterotrophic bacteria to rapidly convert fish waste into natural food for your aquatic plants. It establishes a natural biological balance which makes cycling a new aquarium faster and safer. Eco-Complete is packed in Liquid Amazon buffered “Black Water” solution for immediate organic water conditioning. Unsurpassed macroporosity for healthy roots and bacterial efficiency. You would have to buy 4 bags of ordinary gravel to equal the surface area of this one bag of Eco-Complete Planted Aquarium Substrate! The 20 pound bag of black Eco-Complete Planted sand has a typical grain size between 0.25 mm and 7.0 mm and features an average density of 54 pounds per cubic foot.