What exactly is your question? Are you uncertain how to plumb the unit in for auto-topoff or are you uncertain how to set the unit for a specific dosing volume?
I have pictures of my Pulsafeeder pump on my website at http://www.liquidreef.com/ in the Equipment section under the "DIY Kalkwasser Auto-Topoff System" link. That gives a description of how I have it setup and at the very bottom of the page is a link to a picture index of all the image links on that page.