Pea gravels are used in the lower strata of a filter bed as a support to filter media. For maximum efficiency, the pea gravel must possess necessary attributes of hardness and be rounded or non-angular. The gravel, like filter sand, contains hard durable particles with a slow breakdown rate. This helps to prolong filter media life. The gravel is screened into different sizes which effectively supports the filter media. Also pea gravels are widely used in rain water harvesting system.
Advantages
Free of organic impurities
The grains are smooth and rounded or sub-angular
It is made of hard, insoluble, siliceous material
Uniform in size and quartz based with high silica content