Features and performance:

Pebble (gravel) filter material, commonly known as bearing layer or cushion filter material, is divided into two types: (natural) pebbles and (mechanically processed) quartz are approximately spherical and have a smooth surface. Gravel is made by crushing and finishing quartz ore. It is widely used in water treatment supporting layers such as waterworks, mechanical filters, anion and cation exchange, etc. Common specifications (mm): 2-4, 4-8, 8-16, 16-25, 25-32, 32-50.

Chemical performance indicators：