No, I just wasn't sure if I needed to or not. The CYA test can be a little tricky for someone with terrible eyes. At first I thought my reading (the black dot started to disappear from top view) was 80, but as I continued to add drops I realized my first reading may not be right.
This is my least favorite test and hard for me to read.
If that's all you can find wrong with your water, leave it alone!
http://tftestkits.net sells a standard solution for the CYA test. It is a known 50ppm solution that you use in place of pool water in the CYA test to check yourself. Then you can experiment with the lighting, how far to hold it, etc etc until you know what to do to get an accurate reading.