PH-STOR: pH Electrode Storage Solution by HM Digital Keep your pH probe in peak condition with HM Digital's PH-STOR electrode storage solution. Formulated with a high-concentration KCl (potassium chloride) solution and a built-in fungicide, PH-STOR prevents probe dry-out, inhibits microbial growth, and significantly extends sensor lifespan. Compatible with HM Digital PH-200, PH-80, and most third-party pH meters. Key Features High-concentration KCl formula for optimal electrode hydration Fungicide additive keeps probe junction clean and contamination-free Extends pH probe and electrode life between uses Convenient 60cc eyedropper/twist-off combination cap for precise dispensing Compact size — ideal for lab, hydroponics, aquarium, and field use Product Specifications Volume: 60 cc (60 mL) Contents: Specially formulated KCl solution for pH electrodes and sensors Cap Style: Combination twist-off and eyedropper Country of Origin: Korea Brand: HM Digital MPN: PH-STOR UPC: 891144000113 ⚠ NOT FOR CALIBRATION. To calibrate your pH meter, use a pH buffer solution (e.g., HM Digital BUF-7 or BUF-4). PH-STOR is a storage solution only. Usage Instructions Fill the pH meter's protective cap with PH-STOR solution. The sponge inside the cap should remain moist — not soaking wet. If the probe has dried out, rehydrate by soaking the electrode tip in PH-STOR for 30 minutes before use.