Seachem flourite is a specially fracted stable porous clay gravel for the natural planted aquarium its appearance is best suited to planted aquaria but may be used in any aquarium environmentr flourite is most effective when used alone as an integral substrate bed but it may be mixed with other gravels gravel modifiers such as laterite are not necessaryr flourite is not chemically coated or treated and will not alter the ph of the water although pre washed it should be rinsed before use