You can buy, either from TaylorTechnologies or Leslies, just a FAS-DPD Chlorine test kit that tests FC and CC up to 50ppm. This is the key to Ben's PS-234, Taylor's K-2006C and Leslies FAS-DPD Chlorine Service test kit. You can buy JUST that for about $20 and super-charge your HTH kit.