Chlorine neutralizers that are simply sodium thiosulfate can increase the pH of the solution. So the better thing to do is to get a proper test kit that has special chlorine neutralizers built in using multiple types that offset each other in terms of pH effect. I don't understand why you aren't using the Taylor K-2006 kit after all of this time. You definitely get what you pay for. With this kit, you do not use the chlorine neutralizer -- you just add the 5 drops of indicator dye (with built-in neutralizer) and this should work up to an FC of around 10 ppm before you get significant interference.