[Rikko]

My motivation for writing it was quite simple. A number of aquarists were reporting some very strange pH values from freshly calibrated pH monitors. They tended to be much higher than expected. There was a common thread in these stories: All of them had used a certain brand of pH 10 calibration solution. So, I went to my local pet store, bought some of this product and found that it was low by nearly one pH unit when checked with a research-quality pH meter and electrode, calibrated with fresh research-quality pH standards! In response, I proposed that people at least check their calibrations with another easily obtainable pH standard, a simple solution of borax dissolved in water.