DIAGNOSIS This is normal during filter break-in. Air bubbles and loose carbon fines in the new media temporarily reduce contact time.
FIX Prime the filter with two full reservoirs of cold tap water, discarding both batches as instructed. On the third reservoir, take a TDS reading from water that has dripped into the pitcher for at least 30 seconds. It should now read 000.
IF THAT DIDN'T WORK Your tap water TDS may be extremely high (over 500 ppm). The filter's capacity is exhausted faster. Confirm with your water provider.
HEADS UP The meter itself can fail. Test it by measuring distilled water. It should read 000. If not, the meter needs replacement.