Bluelab PH sensor

Replacement probe for the Bluelab pH Meter, Combo Meter and Guardian. BNC connector, for use in nutrient solution.

The Bluelab pH Probe is the wear part of your meter. The meter itself lasts years; the probe does not, and that is normal: the glass membrane ages through use, however carefully you treat it.

When is a probe finished?

A worn probe gives no error message and carries on producing numbers. Three signs do point to it:

• It will no longer calibrate. The clearest signal. If the meter cannot be brought to 7.0 in pH 7.01 buffer, the probe is finished: not the meter.
• The reading creeps. A healthy probe settles within seconds. If the number wanders for minutes, the membrane is no longer responding properly.
• Readings disagree. Two measurements in the same reservoir, moments apart, that differ noticeably.

If you start doubting your readings and calibration no longer holds, replace the probe before you start changing your feed schedule. A bad reading has you correcting a solution that was fine.

Technical Specifications:

• Fits: Bluelab pH Meter, Combo Meter and Guardian
• Connector: BNC
• Use: nutrient solution and water
• Warranty: 6 months

Frequently asked questions

Do I need to recalibrate after replacing it?
Yes. Always calibrate a new probe before first use.

Can I measure soil or coco with this?
No, this one is for liquid. To measure in a medium, choose the Bluelab Leap probe: it fits the same BNC connector.

Why only six months warranty?
Because a pH electrode is a consumable, not an appliance. Its life depends heavily on storage and cleaning: keeping it wet in KCl storage solution makes the biggest practical difference.