RODI filter replacement

[ajnweb]

At what point do you replace you RODI filters and membrane? I am currently getting a TDS reading of about 7 before the membrane and a TDS reading of 5 after the membrane. So the water I am using to make up the salt water has a TDS reading of 5. What is the maximum TDS reading that one should use to make up salt water?

 

[DonW]

With an rodi it should be 0 after the di. I would double check your meter calibration, doesnt sound right.

Don

 

[ajnweb]

It did originally read 0, but the last couple of weeks it seems to have been creeping up. Could that be an indication that it is time to replace the membrane? The filters look pretty dirty as well.