The Mazzei injector is a simple venturi device which makes it easy to do additions to tanks during a recirculation. Connect the Mazzei injector on the discharge side of your pump which is set to recir culate a tank, drop a short suction hose into the vessel containing your mixed addition (fining agent, carbon, tannin, anything liquid). When the pump is running the venturi will draw from that vessel at a rate you determine with a throttling valve. No need for a stand-alone dosing machine. No hauling buckets of stuff up to the top of the tank. Additions can be made safely from the cellar floor.