During my last recharge (today for a demonstration) I realized that I had not been exhausting the anion before it is recharged. I am not sure that this will make a difference but, I have noticed that my cation does turn purple when it is recharged and the anion does not change color during the recharge process. During the usage of the mixed resins, the canisters never change from a purple to a light brown. I have been changing the resin when the TDS goes up. I began to wonder if the anion did not recharge as well as the cation. This would be why the cation never changed color when the canisters where ready to be recharged.
What I did was after the separation process I removed the anion from the Lye solution and bathed it in the acid solution. It turned a much lighter brown and sunk to the bottom of the container, this would have completely discharged the anion. I strained and rinsed it, then placed it back into the lye solution. Its color became darker and it floated again, this means it has recharged.
For reference the cation is completely exhausted in the lye bath during the separation process.
Any input would be welcome.
I will post the results if the resin changes color when it is ready to be recharged.
For those who are not willing experiment with the process, stay with the original directions until the results, if any, are evident. The resin does recharge fine by the directions.