That test is even less accurate.. only to 2.5 ppm. I am just trying to get a good handle on how much FC loss I am getting per day so I will know how much bleach I am going to need for the summer, and how long I can go before re-dosing the pool. +-1ppm accuracy is what I want. I am keeping my CYA at 40 so my target level is 5-7. The DPD color match won't tell me if I'm at 5 or at 7. The color bands just jump from 5-7.5. I can kind of eyeball and estimate that it's in between those two numbers but there is no way to know if its closer to 5.25 or 7. I just want to get close enough while using as little of the expensive reagent as possible. Thus, the dilution question. It's possible that over the summer we may have someone house sitting for us and I want to be able to estimate how much chlorine per day they will need to add without having to train them in how to perform the test, like "Every other day while we are gone, dump in 20 oz of bleach"
