Ro/di ?

[souk]

how can i tell if i need to change out my ro membrane? i have a DI tester and its stating that its fine. but i have no idea its the membrane is still good. tia, souk

[David Grigor]

You have to test the water coming out of the membrane before the DI to know. The easiest way to mointor is to get one of the dual in-line tds meters so you can see what the reading out of the membrane is at any time without disconnecting the water lines.