The HYDROS pH 7.01 calibration solution works on any pH probe, not just the HYDROS brand. We recommend using at least two points of calibration on a monthly basis to allow the sensors to provide the most accurate reading possible. Using the 7.01 single use packet achieves this calibration process. It is helpful to order enough packets to get through 3 months of calibration. Calibration packets can be stored in a cool dry area for up to 1 year.
