Filter ball are made of 100% polyester fiber, in a network of interlaced strands that are manufactured to prevent the balls from fraying and releasing residues during use, while increasing lifespan. Compared with sand, the tiny fibers can capture more and finer impurities in the water.

Lvyuan fiber Filter balls can certainly be backwashed. Our fiber balls are fixed spheres, formed by ligation process, with stable physical structure, and can support unlimited backwashing. 

And it is lightweight and won't cause much trouble when flushing. It is a good product for making your swimming pool clean.