These crystals are from the storage solution changing from a liquid to a solid. The storage solution is meant to protect your probe from drying out during storage and shipping.
Your probe simply needs to be conditioned to prepare it for use.
To condition the probe, use tap water to rinse the crystals off, then soak the probe in tap water for about 15 minutes.
If the probe has a vent cap at the top (some Hanna probes have this) then make certain the cap is loosened during conditioning.
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