Vivosun Digital pH Tester with ATC

Dissolve a pH buffer packet in 250 ml of distilled water, immerse the electrode, and wait for the reading to stabilize. Press and hold "CAL" for about 3 seconds until the display flashes the buffer value; when it stops flashing, the meter is calibrated. Buffer powders are available in the Vivosun pH Buffer Powder Calibration Kit.

One-point calibration at pH 6.86 delivers ±0.1 pH accuracy and suits most routine testing. Adding pH 4.00 and/or 9.18 for two- or three-point calibration improves accuracy across the wider range, which is useful if you test solutions well above or below neutral.

Automatic Temperature Compensation adjusts readings for the solution's temperature, since pH values shift slightly as temperature changes. This keeps results accurate whether your reservoir is cool or warm.

Submerge the electrode in the solution but never above the marked immersion line on the meter. Stir gently and wait about 30 seconds for a stable reading.

After each use, rinse the electrode with purified or distilled water, dry it with a microfiber cloth, and replace the protective cap. Regular cleaning keeps the electrode sensitive and extends its life.

With the meter turned off, press and hold the HOLD button, then press the power button. When the meter powers on, it's restored to factory settings.

Beyond hydroponic reservoirs and plant nutrients, the tester works for drinking water, pools, spas, aquariums, and brewing.