The pH Pages
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.
pH Measurement and Control for the Planted Aquarium
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.
The Simplest Possible pH Meter
Buying a pH Meter
How to select and buy a pH meter

this may become useful in the future.

--timball

The pH Pages   •   66pacific.com