Is the RO Still Good?
How do I know if my RO is any good?
You can test for that.
With the H2Pro, it's very simple because you divert the RO water to the RO output and you can test the water right there.
On some systems, however, there's no way to divert the RO water. It's plumbed right into the DI cartridge. So with those systems, you remove the DI cartridge from the vessel. Then you put the vessel back in so that you'll only be getting RO water.
This is a great tip if you want to use a system that's closed on a solar panel cleaning job. -- i.e., that doesn't have RO output -- open up your vessel, remove the DI cartridge, and close it up for RO water only.
Now you can use your TDS meter to measure your input water and your output water, and if you're below 10%, you probably still have life in your RO. If it's above a 10% equivalent -- e.g., 400 to 40 -- then you may have an issue with the RO.
However, it could be from a small leak past one of your seals.
To check for this, remove and re-magic glue the seal, relubricate, put it all back together with magic glue, relubricate the o-ring at the top of the cap, then run it again and see if you fall down into that 5-10%. Often that will help.