bluelab pH calibration solution, 4.0 pH, 20 ml
Your meter only measures as accurately as the probe is clean!
PH meters must be cleaned and calibrated regularly to indicate accurate measurements to the user. pH meters should be calibrated to pH 7.0 (buffer) and to pH 4.0 (slope) before each measurement using these solutions. Calibration solutions should be stored in a cool place, out of direct sunlight and heat.
Anonymous (Verified owner) - –
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