Polyethylene Balls are among the newest sand replacement media, with manufacturers touting numerous advantages over sand, including better filtration capacity, less backwashing, longer life and light weight..

For those seeking an alternative to the disadvantages of sand, filter balls or poly balls, are produced by a number of manufacturers and are made with polyethylene, shaped into fuzzy spheres resembling cotton balls.

To replace sand with filter balls, there is no need to change out any filter hardware – simply use an equivalent volume of these light weight balls to replace the sand in a sand filter. According to one manufacturer, 1.4 pounds of filter balls is equivalent to 50 pounds of sand. That means they offer the obvious advantage of being extremely light weight. And clearly, sand cannot be blown into the pool if it is replaced with the filter balls.

Manufacturers claim that they filter smaller particles than traditional sand, with efficiencies varying from filtering 15 to 3 microns, depending on the source.

They also say that the balls are longlasting and are also machine washable. Users recommend washing them in a mesh laundry bag. Furthermore, they are said to reduce filter pressure increases, have high dirt capacity, and are non-clogging.

In practice, they seem to get mixed reviews. Some users find that they don’t last as long as sand, making them a more expensive alternative.

Other say they have had some issues with ineffective backwashing, finding that they were best cleaned by hand or in the washing machine.