OK- I will try to get the OTO kit, but I did try diluting the pool water with bottled water (all I had) and testing using at different concentrations: 1:2, 1:4 1:9 and got zero chlorine reading all times. I got the CYA reading by diluting my pool water with tap water as you recommended: 1 part pool water, 2 parts tap and got around 50 so I tripled it to get 150.