Bluelab pH Calibration Solution is required for optimal performance .
The acidity or alkalinity of a solution is represented by its Potential Hydrogen (pH) level. Values below 7.0pH indicate acidity, while values above 7.0pH mean alkalinity. Variations in pH can have an effect on the nutrient balance of the soil or solution.
 
Conveniently packaged in 500ml bottles to be easily poured into smaller containers for use and to avoid cross contamination.
Specifications: 
2 x 500ml Bottles
Ingredients:
pH 4.0 - Potassium hydrogen phthalate, water
pH 7.0 - Potassium di-hydrogen phosphate, di-sodium phosphate, water
For use with Bluelab pH pen
Features:
Tamper evident lid
Directions for use printed on label
Package Includes:
500ml Bluelab pH4.0 Calibration Solution
500ml Bluelab pH7.0 Calibration Solution
Please note: Please follow directions for use. Use within 3 months of opening.