The process used for removal of all dissolved salts from water is referred to as deionization or demineralization. Deionization requires the flow of water through two ion exchange materials in order to affect the removal of all salt content. Aries Color-changing High-purity Deionization filters provide a resistivity greater than 10 MΩ. Color-changing cartridges provide for easy indication distinctively changing from blue to white upon resin exhaustion, without the need for monitors or indicating lights. Sized to fit standard Slim and BB housings.