EC Calibrating Solution 1.413 should be used to calibrate your Digital EC Pen to ensure accurate readings for optimal growth.
When using a meter to measure either the ppm of total dissolved solids or conductivity of a liquid, it is necessary to periodically calibrate the meter using a calibration standard solution. Although the basis for testing ppm of total dissolved solids is the conductivity of the solution, it is not correct to assume that this measurement is absolute.
It is always necessary to calibrate all total dissolved solids meters with a parts per million total dissolved solids standard calibration solution that contains the same type of salts or mixtures of salts as the solution to be tested. Failure to do this will result in serious errors in the measurement of total dissolved solids.
Refer to Digital Pen instructions for type of calibrating solution required.