GRANULATION 1-1,5 mm high quality, natural. GENERAL GUIDELINES FOR 4-5 cm GRAVEL DEPTH IN ARROUND 1FT LONG AQUARIUM This type of sand is ideal for MALAWI TANGANIKA AQUARIUM as it raises pH of the water, giving an alkaline reaction. Sand will require rinsing before use and is a little more likely to make the new water cloudy for a short time whilst it settles. Our sand is not artificially coloured! It is 100% natural and 100% safe! You can rely on our experience!