Caribsea Eco-Complete Planted Aquarium Substrate is one of our most popular products - and no wonder, its brilliant! Grain size 0.25-7mm Contains Iron, Calcium, Magnesium, Potassium, Sulfer plus 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! The Eco-Complete is Iron rich which eliminates the need for laterite and is also Nitrate and carbonate free which will not increase pH or carbonate hardness. There is no artificial dye, paint or chemical coating because it`s real! The Eco-Complete also contains live Heterotrophic Bacteria to rapidly convert fish waste into natural food for your aquatic plants. The Eco-Complete also creates a natural biological balance which makes cycling in a new aquarium faster and safer. With it`s unsurpassed MacroPorosity for healthy roots and bacterial efficieny - you would have to buy 4 bags of ordinary gravel to equal the surface are of this one bag of Eco-Complete Planted Aquarium. Typical Size: 0.25 - 7.0mm