Taylor K-2006C Complete FAS-DPD Test Kit with 2oz Solutions $146.10 2000 Complete, Alkalinity/Chlorine (hi range), FAS-DPD/CYA/Hardness/pH K-2006C with 2oz Solutions In recent years, professionals in the pool and spa industry have progressed from using orthotolidine (OT) to N,N-diethyl-p-phenylene-diamine... Add to Cart