Bluelab PH 7.0 calibration solution 250 ML

A 250 ml bottle of Bluelab pH 7.0 buffer. The size for anyone calibrating regularly.

A calibration routine you will actually keep

Everyone knows you should calibrate. Almost nobody does it as often as they intended, and rarely through unwillingness. It is because there is no moment at which it happens by itself.

What does work is attaching it to something you already do.

• At every reservoir change. You are standing there with your meter anyway, the tank is empty and you are mixing fresh. Calibrate before you mix, and you know you are setting up against a good number.
• At the start of every crop. The moment an error does the most weeks of damage, and therefore the moment you least want to be guessing.
• After every electrode clean. A clean probe reads differently from a dirty one, that is the point, so recalibration follows.
• The moment you distrust a reading. Not later, immediately. This is exactly how you find out whether it was your solution or your meter.

At that rhythm you land on roughly one calibration a month, and a 250 ml bottle then lasts you something like a year to eighteen months, provided you use it sparingly: a shallow pool in a clean pot, and never poured back.

Note the date you open the bottle. Buffer ages once air reaches it, and a bottle open longer than a year has become a suspect in its own right.

Technical Specifications:

• Value: pH 7.0
• Volume: 250 ml
• Brand: Bluelab
• Use: first calibration point (zero point) on any pH meter

Frequently asked questions

How many calibrations do I get from 250 ml?
Roughly twelve to twenty, depending on the size of your calibration pot.

Do I need 4.0 as well?
If your meter calibrates at two points, yes. That corrects the slope of the scale as well as the zero point.

Can I take the bottle to my reservoir?
Better to take a pot with some liquid in it. Calibrating in the bottle is the fastest way to contaminate your whole supply.