Lanlang has two type color changing di resin.
Color changing di resin will physically change colors as it gets exhausted. That allows you to monitor the consumption of the DI resin and know when to change it out. If you have a TDS meter we still recommend color changing resin as it will let you know when to monitor your TDS meter for when TDS starts creeping through the DI resin.
Lanlang’s color changing di resin list ：
Color changing, cation resin indicator
Color changes from green to yellow after exhausting
Color changing, anion resin indicator
Color changes from blue to yellow after exhausting