Stop using sand in your filter! Easier to use, cleaner to change, better filtration! Replace the sand in your new or existing sand filter with Filtra Balls Filter Media and experience the difference! Reusable, eco-friendly and made from 100% polyethylene, these tiny balls will last for years while filtering particles down to 3 microns. 1 box of Filtra Balls is equivalent to 50 pounds of normal filter sand! Note: Is it recommended that you still add some sand (approx. 1 bag) to the bottom of your filter tank, prior to adding Filtra Balls, in order to support the filter laterals.