pH Calibration Solution 4.00 Use this solution to calibrate your pH probe primarily when you will be using it in a low-pH application such as a calcium reactor. It is not usually used to calibrate your pH probe for use in your aquarium itself.
pH Calibration Solution 4.00 Use this solution to calibrate your pH probe primarily when you will be using it in a low-pH application such as a calcium reactor. It is not usually used to calibrate your pH probe for use in your aquarium itself.