Quote Originally Posted by Joshua
Check your RO (before DI) water to make sure your membrane doesn't need a swapping. If your membrane is putting out high TDS it'll waste your DI in no time flat. I had calcium deposits that killed my RO membrane and in turn killed the DI so had to replace them both.
Not what I wanted to hear. I had to replace the water heater cores due to calcium deposits and the house isn't even 2 years old. Man I regret not getting a water softner. It would pay itself in just a few years.

I'll check out the membrane.

I tested the water directly out of the RO/DI, not mixed with the old RO/DI water and it was 22 TDS stil not good at all. I'll check what it is after the RO membrane before the DI cartridge.