Review on 📈 APERA INSTRUMENTS AI209 Value Series PH20 Waterproof pH Tester Kit - Accurate to ±0.1 pH by Carmen White

I am a retired chemist and I highly recommend this instrument. It is important to have a device that can be calibrated. Be sure to rinse the probe with deionized or distilled water after use and always store in 3M KCl. The calibration instructions aren't clearly written, so I recommend watching a YouTube video that walks you through the process. You can also purchase pH 7 and pH 4 or pH 10 buffers to use for calibration. The number of supplied buffers is not unlimited. You can also make your own probe storage solution (3 molar Kcl). Dissolve 225 grams of KCl in 1 liter of water, or half that amount in 1 liter of water. Always use distilled or deionized water. If you are looking for a pH range of 7 to 4, use these two 2-point calibration buffers. Use these buffers for a range of 7 to 10. For a range of 4 to 10, perform a 3-point calibration with 3 buffer solutions. I use my hydroponic test meter and it works well.