The instrument is only as accurate as the probe is clean. Probe cleaning is one of the most important parts of owning or operating any Bluelab meter, monitor or controller. The probe surface is where the instrument takes the reading of the solution. If the probe face is dirty or contaminated, then the reading will be inaccurate. Accurate readings simplify crop management and provide improved growth. To re-stock your conductivity probe care kit, Bluelab 2.77 EC Conductivity Standard Solution is available in 20 ml sachets, 250 ml and 500 ml bottles. Probe Tips All probes are interchangeable between all Bluelab products All probes carry a 6 month warranty Proper hydration of pH probes is vital to maintain wick All pH probes eventually need to be replaced—they can only house so much reference solution KCl storage solution is required for optimum probe maintenance RO water will reduce probe life