There has got to be a better way....

[tadcpht]

Could someone please help me out determining the best most accurate way to find out the cya level? I have a Taylor 2005 test kit. The cya markings go from 30-100. The way I have been doing the test seems extremely subjective. I mean the disappearing little black dot? I can't tell if I see it or not, or just the way I'm looking down at the tube, the way the sun is pointing. I get ranges after anywhere from less than 30 to 40. This leaves me with what target FC level to go with. I have tried to be consistent with my back towards the sun and the tube in the shadow but I just never get the same reading. Is there a better testing method or am I just stuck making educated guesses?

 

[Texas Splash]

Nope - you're stuck. We all are. Just practice and keep using the same mixed solution to go back & forth multiple times to try and get a good average result. It can play tricks with your eyes. Perhaps pour some into the viewing tube, look away briefly, the re-focus on the dot. Have someone else try as well a couple times to compare results. In time you'll become more comfortable.

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Here's the video: Testing Cyanuric Acid with the TF-100 - YouTube

 

[Donldson]

If you feel you need to calibrate your testing you can get a standard solution: TFTestkits.net

Use that and find the lighting that gives you a reading of 50 and that is the lighting that will give you the most accurate result when you test your own water.

 

[Richard320]

You can order a 50 CYA standard solution. Mix it up just like you would pool water and then experiment with lighting and hand positioning and distance until you see 50. Then repeat the test using pool water under exactly the same conditions.

It's R-7065 solution. You can order any other refills or a speedstir at the same time TFTestkits.net