This is the way I test CYA. Once I learned that I don’t actually have to pour it while watching for the dot to go away, the test got a lot easier. I just keep putting it at different lines (levels) until I’m comfortable that I’m getting a good number.CYA test
Remember, GLANCE to see the dot - do NOT stare.
- Mix the pool water and R-0013 as directed in the instructions
- Outside on a sunny day (near noon if possible)
- Back to the sun
- Mix the testing bottle again
- Fill vial to a line on the test vial - say 70
- Lower vial to waist level in the shadow of your body
- GLANCE and look away
- See the dot? Fill vial to next line
- Rinse, repeat until you don't see the dot
- If you see the dot at 50 but don't see it at 40, your CYA is somewhere between 40 and 50 - so it gets rounded up to 50
You can put the test solution back into the mixing bottle numerous times and do the test again.
Some do the CYA test this way three times to better determine the result during that testing cycle.
You may not have taken the CH and TA test to their true end result. See the recommendation for these two test in post #24 above.
Regarding the PH - I hold my vial up to the clear blue sky and also down at some concrete (almost white) when I do the test. Remember, PH has a pretty large acceptable range. You’re basically trying to keep it in the 7’s. Yes, you want to be in the high sevens, but if you’re struggling to determine if it’s 7.6 or 7.8, you can just pick one and move on. Next time you do the test, ask yourself - can I easily tell that I’m over 7.4 and under 8? If so, you’re good to go.
Same thing with CYA. There’s not a lot of difference in how you’ll operate if your CYA is between 50 and 70. You’re just trying to make sure you have a good amount of stabilizer in your pool. It might help to be more precise if you are SLAMing your pool (a process to get rid of algea), but in day to day operation, precision doesn’t matter so much. As you get more comfortable with what you’re doing, you’ll understand the cya/chlorine balance and be able to relax a bit. For example, my cya is around 60. Recommended chlorine level is 4-9. SLAM level at that cya is 24. It’s safe to swim up to the SLAM level. So keeping my chlorine on the high end of the range or a bit higher is all good. I run my VSP pump 24 hours and my SWG is at 20%. That keeps my chlorine around 12. Close enough and the pool is clear and no one has ever had any issues with my water. No chlorine smell, no burning eyes, no complaints. All thanks to TFP.