Aqua Medic electrodes are quality products, designed for both accurate measurement and long trouble free use. The pH- and Redox (ORP) electrodes can be used with all Aqua Medic measuring units, but as well with most compatible standard instruments with a BNC port. For regular check-up and calibration, we recommend to use the Aqua Medic test fluids for pH value and Redox. Electrode holders are available as an option. They can hold up several electrodes and can be attached to the horizontal or vertical stress bars inside the aquarium. From the protective cap, KCI solution can leak during transport and storage, forming crystalline, white potassium chloride. This salt layer has no influence on the measuring ability and can be easily rinsed off with water. Immerse electrodes only a few centimeters into the measuring medium. Each electrode ages as a result of the exchange processes on the glass membrane. pH and mV electrodes are therefore consumables and subject to wear and tear. Therefore, the warranty for pH and mV electrodes is limited to six months.