How often to change the RO/DI filters?

[monpeasch]

Hi,

Are there some guidelines to follow on how often to change these filters?

My Pre Filter I can see when it's dirty and change it.

The Carbon filter doesn't show any change in color so how often to change that one?

The DI filter changes from black to sort of orange so I can see that one..

Also, just wondering if the water quality changes with the seasons. During the warmer months, my pre-filter got dirty pretty quickly. Now that it's winter, it's hardly changed at all. I live in Northern Virginia, Fairfax County.

Thanks!

[Geoff]

i like to use a TDS meter. even though my DI cartridges is showing all brown it is still doing its job of keeping the TDS of the water below 5.

G~