In terms of sand filtration (rapid / slow filtration), the maintenance of filters largely depends on the particle size and uniformity. Therefore, the selection of the quality of filter sand is very important. The properties, size, quality, and conformity play an important role to satisfy JWWA standards.
Only about 30% of the particles in natural sand can be used for rapid filtration, because it requires uniform particle size, and sieving via an advanced technique. NIHON GENRYO has provided the cutting-edge technology to produce for rapid and slow filtration for more than 80 years. Our original sieving, and physical and chemical tests are conducted according to our strict standards to provide high-quality filter media to the market.