STORE PICK UP ONLI - Does not ship Flourite is a specially fracted stable porous clay gravel for the natural planted aquarium. Although it may be mixed with other gravels, Flourite is best used as an integral substrate bed. Any mixture should be at least half flourite. Gravel modifiers such as laterite are not necessary. 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 to remove residual dust. Slight initial cloudiness is normal and will clear rapidly. Each 7 kg (15.4 lbs) bag is sufficient for about a 2 inch deep bed in a typical 10 gallon tank. Recommended use is 1 kg for about each 200 cm2 (31 in2) of tank bottom.