To get accurate readings using a 'cheap' pH meter, the user must use a
scrubby, such as a Scotch-brite pad to polish the (oxidized) tip. If the
tip is gray in color, it is oxidized and won't give an accurate reading.
The tip needs to be a sparkling silver color. Equally important is that the
medium to be tested be thoroughy saturated - if too much water is added, the
pH reading will be affected by the pH of the water. Before expecting a pH
reading, allow the material to completely drain before taking a reading.
--
Jim Fruth
Brambleberry Farm
Pequot Lakes, MN
www.bberryfarm.com