Hi, demin water of that quality should not drop just like that. If storing the volume the tank should be sealed, on some applications a Nitrogen blanket is used above the volume of the treated water.If recirculating prior to use you may want to install a polishing cylinder.
Using yes no tablets for testing a softener shortly after a regeneration should indicate red for hardness and green for soft.Green would be good to go, but if slight red is indicated can also be down to high chloride carry over from the brine.Using a hardness test kit (titration)indicates less...
