Thank you for contacting ZeroWater. The most accurate way to get reading is to test the water directly inside the pitcher. You can do this by removing the reservoir from the pitcher and sticking the meter in the filtered water sitting in the pitcher. If you get a 000 reading inside the pitcher it is possible that the cup or glass you were using before had soap residue on it causing the meter to read above 000.
If you are not getting 000 in the pitcher, try the following steps to see if you can get the filter to read 000 on the meter.
Dry off the filter with a clean paper towel. Then place the filter over a clean paper cup.
Run a small amount of water directly into the filter and test the water that collects into the cup. If the meter does not read 000 it is possible that unfiltered water got into the pitcher via a leak at the O-ring. In order for filtered water to read correctly there must be a perfect seal where the filter is screwed into the reservoir. Make sure the filter is screwed in from the bottom not dropped in from the top. Additionally, from time to time; the filter can develop an air lock, some little air pockets or air bubbles that get trapped down inside the filter. Typically this is an easy and quick fix, simply remove the filter from the container and unscrew it from the tray. Then hold the filter sideways/horizontal and grip the filter very tightly and shake the filter with some good force side to side and back and forth 8 to 10 times. This will loosen the filter media and break the air lock.