Keeps every pH reading honest — calibrate before you dose, not afterA pH meter is only as accurate as its last calibration, and electrodes naturally drift out of true with regular use, so growers who skip calibration are effectively guessing at pH without realising it. This is a NIST-traceable pH buffer solution used to check and reset a meter or probe against a known, fixed reference point before feeding, available in the two standard buffer values — pH 4.01 and pH 7.00 — needed for a proper 2-point calibration.It works with any pH meter or pen, not just the Aqua Master Tools range, making it a sensible bottle to keep on the shelf regardless of which brand of meter is in use. Running a 2-point calibration regularly, ideally before every reservoir mix or at minimum weekly, catches probe drift before it turns into an under or over-corrected feed — a meter reading half a point off pH can be the difference between a nutrient solution sitting comfortably in the uptake range and one that is quietly locking out phosphorus or micronutrients. NIST-traceable buffer solution for accurate, repeatable calibration Available at pH 4.01 and pH 7.00 — the two points needed for a full calibration Works with any brand of pH meter or pen, not just Aqua Master Tools Catches probe drift before it causes dosing errors Simple top-up bottle to keep on the shelf by the reservoir Buffer values: pH 4.01, pH 7.00 Standard: NIST-traceable Storage: 15-25°C, reseal immediately after use Note: do not return used liquid to the bottle
