Growth Technology Buffer 4

Keep your pH readings honest and your feeds correct

Growth Technology Buffer 4 is a precision calibration fluid fixed at exactly pH 4.00, used to check and set the low-end point on pH pens, handheld meters and inline controllers. Every glass pH probe drifts over time, and a meter that has wandered even a few tenths will have you chasing a feed problem that never existed, or miss a real lockout building in the reservoir. Calibrating regularly against a known 4.00 reference keeps every reading you rely on trustworthy.

Key Benefits

• Fixed pH 4.00 reference gives a stable, repeatable low-point for accurate two-point calibration.
• Universal compatibility with pH pens, handheld meters and inline dosing controllers.
• No mixing or measuring - ready to use straight away for a quick calibration check.
• Protects feed accuracy so pH Up and Down are only used when the solution genuinely needs it.
• Colour-matched to standard buffer conventions for easy recognition alongside a pH 7.00 solution.

Drifting probe sending your whole feed off course?

An uncalibrated pH meter is one of the most common hidden causes of nutrient lockout and stalled growth. When the probe reads high or low, you correct a feed that was already fine and push it out of the uptake window, starving the roots of otherwise available nutrients. Regular calibration against Buffer 4 removes that guesswork at the source.

How to Use

• Rinse first: flush the probe with clean water and shake off the excess before dipping.
• Dip and settle: immerse the probe in the pH 4.00 solution and wait for the reading to stabilise.
• Set the point: adjust the meter to read 4.00 following its own calibration procedure, ideally as part of a two-point calibration with a pH 7.00 buffer.
• Rinse and store: rinse the probe again before returning it to use, and never pour used buffer back into the bottle.
• Recalibrate regularly - every few weeks, or before any reading you need to trust.