Hanna Instruments Electrode Storage Solution HI70300L (500 mL)HI70300L is a storage solution prepared with reagent grade chemicals that can be used to ensure optimum performance of your pH and ORP electrodes. It is necessary to store a pH electrode in a solution in order to keep the glass membrane of the pH electrode hydrated. Ideally a storage solution should be used; never store an electrode in distilled or deionized water. The Hanna Instruments storage solution is specifically formulated to minimize microbial