Flourite Gravel is a specially crafted stable porous clay, perfect for the natural planted aquarium. Its appearance is designed for a plant aquarium but can be used in any aquascape. Flourite Gravel is most effective when used alone as an integral substrate bed, but it may be mixed with other gravels. Flourite Gravel is not chemically coated or treated and will not alter the pH of the water, the best part is, it’s also good for the life of the aquarium and doesn’t need to be replaced.