worked today with 7ppm it was fine... so i just filled my tank up and i thought it would go up to 9 or 10.... but now i got a full tank of 15ppm ! ill have to use that for tomorrow :| changing my resin aswell now i was just wondering.... if i have water left over..... do i have to empty it to put new water in ? if i put new filtered water in my tank will my water be 00ppm ? or will it still be 15ppm ? I got a tap at the bottom so i can just empty it out. ( all of my water does not empty out of the tank theirs always a bit left at the bottom because my tap is just above the bottom.