I have used chem-feeders for years with chlorine, hydrogen peroxide and sodium hydroxide. Stenner pumps are easy to maintain and it is simple to replace the tube. Yes, they do come with an extra tube at no additional cost. This is, in part, due to the necessity of quick replacement in the event of failure or scheduled maintenance so that water service is not interrupted for long.
I prefer peristaltic pumps as they don’t need priming like diaphragm/reed models, which we routinely replace. Since we are responsible for the products we sell, we want to make sure they work well and long.
Stenner pumps can come with a dual feeder for completely separate chemical feeds. The switch can be attached to the pressure switch and injector point anywhere on the line after the pressure tank, tee, gauge, etc.
When water is being used that is not to be treated, say for irrigation, then a flow meter and switch modulator can be added to activate pump only when treated water is in demand. By monitoring flow in service lines. It cost more but works very well.
Andy Christensen, CWS-II