Uploaded March 2025 | Updated September 2026, 1 day ago

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Karl shows us how to keep your OnePen readings accurate with these simple pH calibration steps:
1️⃣ Select pH measurement mode and ensure pH reading is displayed
2️⃣ For pH7 calibration:
Submerge probe tip in pH 7.0 solution
Hold "CAL" button until "CAL" appears, then release
Wait for dots to stop flashing and "PASS PH7" to display

3️⃣ Rinse in fresh tap water
4️⃣ For pH4 calibration:
Submerge in pH 4.0 solution
Hold "CAL" until "CAL" appears, then release
Wait for "PASS PH4" to display.

A successful calibration will show the tick ✅ icon and 4 & 7 circles will be visible!

💡 Regular calibration extends probe life and ensures accurate readings. Clean your probe before calibrating for best results.
#BluelabOnePen #pHCalibration #HydroponicTips #GrowingSuccess