CYA test subjectiveness?

[striperseeker]

It's nice to be able to test for CYA at home instead of going to the local pool shop. However, the test seems so subjective to me. Maybe it doesn't matter if it's 10-15 units off, but when I look at it at waist level and my wife looks at it as well, we see the black dot at different intervals probably due to eye strength and glasses? IDK.
Anyone else think this?
TIA

 

[Msch99]

It can be challenging! I bought a standard solution (50 I think) to calibrate myself with.
You can dump the solution back into the bottle and do the check multiple times also. Take an average.
If your kit is like mine(tube with dot in bottom). I fill to a safe line then lower to waist level to assess. Raise up and fill to next line, lower, check again. Helps me anyway.
Good luck!

 

[Jimrahbe]

SS,

It just does not need to be that accurate.. Once you do the test a few times it gets easier. If you want say 70 ppm, as long as you can tell that it is over 60 and under 80, you are close enough..

Thanks,

Jim R.