NOTE: Due to the nature of the material, Siliphos balls may crack into shards during shipping. Shards can still be used as normal, and may allow you to squeeze a bit more material into a filter housing. Diameter of Single Ball: 3/4 (0.75) inch Scale - Used to sequester water hardness, inhibit precipitation, and formation of mineral deposits in pipes & appliances. Corrosion Inhibition - Used to form a protective coating on metal surfaces Iron Control - Used to sequester dissolved iron up to 10 ppm