Some testing tips for you... If you're unsure of the CYA reading / result, you can retest with the same sample. Just pour what you got into the test tube back into the little dispensing bottle with the remaining leftover sample, shake, and then pour it back into the test tube for another look. No need to use more reagent for another test. Also, it is best to look down the tube in outdoor daylight with the sun at your back. Lastly, the pH reading will be artificially high due to the high amount of FC you have. So, don't let that surprise you.