20ml single-use Bluelab Solution Sachets, 2 each of: pH 7.0 & pH 4.0, KCl, 2.77 EC. Bluelab pH Probe Cleaner. Bluelab Conductivity Probe Cleaner. If the information sent back from the probe is inaccurate due to probe surface contamination then the reading will be inaccurate.
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