RO/DI change out questions

[oldbenkenobi]

I have a BRS 7 stage ro/di system that has been up and running since September. How do I know when it is time to change the filters/membranes?

 

[CuzzA]

I have a BRS 7 stage ro/di system that has been up and running since September. How do I know when it is time to change the filters/membranes?

A lot depends on how much water you are producing and the quality of your utility or well water. Generally speaking, change the sediment when it turns yellow/brown (3-6 months). The carbon block every six months, the RO membrane when TDS IN exceeds 7-10 and DI when TDS OUT exceeds zero.

If you wanted to get more precise you could add another digital TDS meter with the IN monitoring your utility water and the OUT monitoring the output from the carbon block. This would give you an idea of the diminishing capacity of the sediment and carbon filters, however I don't know what the number or spread would be to determine when to change them.