Well, here is what I am using. Project is not complete yet but, I have a Masterflex peristaltic pump head purchased off Ebay for about $25.00, included a mounting bracket. These heads are very reliable and long lasting.
Coded a PIC 18F1330 for the control portion of the project including a LCD display. It is adjustable from 1ml to 120ml a min. The PIC outputs a square wave to a L297/L298 stepper driver to a PowerMax II stepper motor I had on hand. This stepper, via a 1/4" coupling turns the Masterflex peristaltic pump head.
Has been running flawlessly for the last 3 months sitting in it's breadboard form.
Part 2 of the project will be controlling the CO2 from the regulator to the calcium reactor using a Clippard electronic valve.
http://www.clippard.com/store/displa...?sku=EV-2-12-L
This should make dialing in the reactor much easier.
Finally will put the whole thing on a PCB and in a appropriate enclosure
