From your post I'm assuming that "all media" that you changed included the sediment filter, carbon block, and DI resin, but not the membrane.
At least half the time when customers contact us with issues like this, the problem is inaccurate TDS readings. These can be caused by things like:
*taking TDS readings from TDS creep water
*probes on in-line TDS meters not being aligned properly
*using sample containers that aren't clean
If your readings are accurate, some things that might cause you to burn through a resin refill quickly:
*bad DI resin (resin was old when installed, or resin was from a source where it may have sat on the shelf for an extended period before you bought it, or the resin was just poor quality material)
*bad RO membrane sending high TDS water to the resin
*internal crack in the RO membrane housing letting waste water make it to the DI
*low water pressure affecting membrane performance
*RO membrane not fully seated
So to get started, we need some more information.
1. What is your water pressure?
2. What is TDS of your tap water?
3. What is TDS of your RO water?
4. What is TDS of your DI water? Is it really 26 ppm?
5. Are you sure your TDS readings are accurate?
Russ
