The pH Pages
pH meters, pH measurement, and pH control for aquariums, or whatever your needs
pH Measurement and Control for the Planted Aquarium
Build a simple and inexpensive pH meter. Additional circuitry enables you to control
CO2 injection in a planted aquarium to stimulate plant growth.
The Simplest Possible pH Meter
You can build a super-simple pH meter with just a pH probe, an op amp, two batteries, and a voltmeter.
Buying a pH Meter
How to select and buy a pH meter
Calibrating and Caring for a pH Meter
How to calibrate a pH meter.
pH Measurement Components
Components for measuring and controlling pH