I am looking for an easier way to dose the B-Ionic 2-part additive to my system. ESV sells an automatic doser that looks like it would do the trick, but it's almost $200. Just wondering if anyone here has one and if they think it's worth the money. Also it looks like it wouldn't be too difficult to build one. Just not clear on how the "Air vent & Air/Liquid Separator" part works (see the diagram here...http://www.esvco.com/prod9.html).