I'll start by saying I hate the CYA test. Never can decide about the black dot.
Somewhere I have read a post where someone posted how to measure the percentage of chlorine in your bleach involving taking one liter of DI water and a 1uL syringe of bleach, and doing the FC test to measure the amount of chlorine that you have. This is handy to determine if your bleach has gotten old and is no longer full concentration.
This got me to thinking. I hate the CYA test. I have such a hard time deciding if I can see the black dot or not. So I was wondering if someone had come up with a method to make a CYA water standard that you would know is say 50ppm (or any number that you know) so you can test it and make sure that you are reading your water correctly. I was thinking something like taking 1 liter of DI water, adding X ounces of stabilizer. Someone far better that the pool math would need to help me out with the math, and maybe it would need to be made with 1 gallon of water, or 5 gallons of water.
Can anyone help me with this idea?