Bluelab pH Cleaning and Calibration Kit

Everything for maintaining a pH probe in one box: cleaner, brush, three pots, and sachets of pH 7.0 and pH 4.0 buffer plus KCl storage solution.

The full maintenance round, in order

A pH electrode is the one part of your measuring kit that genuinely wears out. How long it lasts depends almost entirely on what you do in these four steps. The order is not optional.

1. Clean. Nutrient salts and biofilm build a film on the glass. Use the electrode cleaner supplied, and the brush as described in the instructions. Never use abrasives or washing-up liquid: the first damages the membrane, the second leaves a film behind.
2. Hydrate. Stand the probe in KCl storage solution after cleaning. Cleaning disturbs the membrane briefly, and it recovers in a solution with a high ion concentration.
3. Calibrate. pH 7.0 first as the zero point, then pH 4.0 for the slope, rinsing with clean water in between. Calibrating before cleaning is pointless: you would be setting the meter up against a fouled probe.
4. Store. A few drops of KCl in the protective cap. Never dry, and never in deionised water, which pulls ions out of the membrane instead.

Do this round monthly and at the start of every crop. The three pots in the set exist to keep the liquids apart: pour, use, discard, and never put anything back into a sachet or bottle.

Technical Specifications:

• Contents: instructions, 3 plastic pots, 20 ml sachets of 2 x pH 7.0, 2 x pH 4.0 and KCl storage solution, Bluelab pH electrode cleaner, 1 cleaning brush
• Brand: Bluelab
• Use: cleaning, calibrating and storing pH electrodes

Frequently asked questions

Can I use the brush on the glass membrane?
Use it as the instructions describe and with a light hand. What damages a membrane is scouring and abrasives, not the soft brush Bluelab supplies.

How often should I do this?
Monthly with regular use, and always at the start of a crop or when you distrust a reading.

My probe still will not calibrate after cleaning.
Then the electrode is probably finished. That is normal: it is a consumable, not an appliance.

Is there enough in here for a whole season?
The sachets are meant to get you started. Calibrating monthly, you will top up over time with separate bottles of buffer and storage solution.