Hello all, im on the process of buying a test kit, looking at the K-2006C or the TF-Pro kit, but when i went to the TF-Pro website i saw they sell a TF-Pro Salt and was wondering if i have a SWG if i need to get that salt kit? What is the difference between it and the regular TF-Pro? is it to determine salt levels in ppm? My old hayward did that for me, it displayed the salt in ppm on the SWG control box, dont they all do that?