Nice setup on the SWCG.
Is your TA really 750??? Seems awful high - could be a testing error. Remember this is a 25ml pool sample.
I think you meant TC was 8.0 but we really only use FC and CC so that would have been 8.0 and 0.0 respectively
Your FC will need to increase if you really have CYA of 100. Try this method for testing however if you cannot see this dot at 100 mark then you are 100 or higher. Therefore you may need to do the dilution method test.
Take the CYA bottle and fill it half with pool water and the other half with tap water. Tap water has no CYA. Shake it up well, then pour half out such that the remainder is your “diluted pool sample”. Then fill the bottle with the R-0013 Reagent as per the test directions. Shake it well and let sit for 30 seconds. Then pour into the CYA tube to read the CYA value. Whatever is your value you need to multiple it x2. So if you now read 60ppm, then your real CYA is 120ppm. It is not perfect but provides a better value then being >100.
Also, you may want to try this method for reading your CYA as I find it easier and avoids staring at the dot as you pour.
Pour the mixed solution to a known level, say 90, peer in and confirm you can see black dot. Now pour mixed solution to 80 mark, peer in again, if you can still see dot, hold tube up and pour mixed solution to the 70 mark, then peer in again to view dot. Continue this until you are not able to see the dot - then use your CYA number as the value you last saw the dot. This method avoids constantly looking down the tube which can create the illusion of always seeing the dot due to staring down the tube. This also helps that you only report CYA values in decade numbers due to the logarithmic scale of the tube.
