◆ Filter Gravel
Filter gravel does not filtrate directly, but it acts as a supporting layer, preventing filter sand from entering into an underdrain. It also plays very important role to provide backwashing water evenly. To make the best use of the filter media, it is important to use filter gravel with the selected quality. The filter gravels out of standard are removed by hand, such as flat, cracked and fragile gravel with seashells. Therefore, we can always provide the high-quality rounded gravels in the market.