pH 4.01 Calibration Solution

We recommend that you calibrate you pH meter regularly. This Calibration Solution is used to adjust your pH meter to 4.01. Easy to use, just dip your electrode into a small amount of the buffer and adjust the meter to read 4.01. Do not reuse solution. Suitable for all makes and models of pH pens and meters.

General Hydroponics reference solutions are of the highest quality, allowing growers to calibrate many popular brands of pH, EC and TDS meters (NaCl scale or the 442 scale). General Hydroponics technicians check each batch to ensure that our solutions are precisely calibrated and yield reliable readings each time they are used.