Robuta

https://www.wecofilters.com/fdi-1025.html WECO FDI-1025 Color Changing Deionizing (DI) Mixed Bed Resin Filtration Kit TDS removal cartridge unit. Anion component infused with a permanent pH indicator dye that chat changes color from blue to amber as the resin exhausts. wecofdicolorchangingdeionizing