Good luck. From what I have seen they are very expensive and for non-residential systems. Most systems, my Hayward Pro Logic included, work off of % of cells capable output. This very much frustrated me due to needing to balance that setting and the fact it is on all times when pump is running.... I got used to it. Once you find right settings after a few weeks of trial and error, all is good. My settings for a 19k vinyl IGP are - 1HP pump at low for 12 hours per day and IC-15 cell/Prologic setting at 15%. This keeps me around 7ppm, which is where I like it.