A Do It Yourself PH Controller

NEW in 2008!
 - I've taken a renewed interest in this project and will be soon reviving it, complete with an interface to a solenoid.   This is preliminary information about an incompletely tested design, but gives you an idea of where I'm headed.  Also once I get the design checked out, I plan on designing a board to ease implementation.  I may even get a few extra made and offer them for sale, if there is interest.

Even if you don't need a PH controller of this type, this project should provide the attentive builder with a some basic understanding of op-amp circuits.

A couple of years ago, I was going to go all out and put together a nice planted aquarium with CO2 injection and everything else.  Although the planted aquarium never really happened do to the plague of algae documented elsewhere,   I did do a prototype PH controller.  I was going to use a commercial CO2 bottle, but after experimenting with yeast CO2, I never took the that next step and have never installed this controller.   Those who wish to try making their own PH controller based on this design should be forewarned that this design has not been actually installed and left operating.
The basic PH controller idea came from Gary Bishop's design which can be found at http://www.thekrib.com/Plants/CO2/co2-pvc.html.  Anyone attempting to build one, should first reference his design as he has some insight about actual operation.  My implementation has a slightly different design for the probe's light box and electronics.

Let me know if you try this design and if you encounter any problems or have ideas for improvements. 
  • The Probe
  • A CO2 Reactor (coming soon)
  • The Revised Electronics
  • The Original Electronics


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