pH buffer 4
pH buffer 4 and 7 solutions from Growth Technology are of a known and fixed pH, which are used to calibrate your pH meter and should be done on a regular basis to ensure ongoing accuracy from the meter.
pH Buffer 7 will calibrate your meter to neutral and we recommend you then use pH buffer 4 to calibrate your meter to this level, this will give you a two point calibration.
Top Tip: It is wise to pour out a small amount of Buffer solution into a container to calibrate your meter and when finished, discard the used solution. Do not pour it back to the container as it will contaminate your unused solution.