Just done my first resin change, and lo and behold, timing or what, the tds meter just reads 0 on everything. even tap water. It worked about half hour before production as I tested our tap water and was as normal. I know, I should've had a spare, now gonna order 2 more from daqua. So I need this water monday and cant get one in time so having to chance that its ok. With new resin you'd have thought so, though I have had it sat there over a year( unopened) So is there a way to fix it, or do they just go after a while? Battery is obviously working. Cant get over the timing, nightmare.