[Lazarus]

Filling technique is critical. Make sure during the calibration period that you run the tank to empty and not just 3-5 gallons. Fill at the same pump and use the same technique every time. If you just go to the automatic shutoff on the pump then do that or if you go to the next shutoff then do it the same every fill. Consistency is key.

I had mind down to .1 on every fill. If you are already doing these things maybe there is something else going on. Unless your unit resets itself every once and awhile and goes to the default setting.