CYA question

[imcj]

I'm sure this is going to be a "duh" question but here goes...

My CYA has been testing consistently at 80 for a month (TF-100 kit). A few days ago I tested CYA and it was 90. I haven't added any CYA, so my assumption is I just performed a bad test and should just test again, right? It can't go up without adding!

 

[257WbyMag]

It won't go up unless you added some. You can get some variance on the test because there is so much left to personal interpretation. Even changing the time of day that you test it can make it look different due to the difference in available light.

 

[JasonLion]

The CYA test is not especially precise. Two CYA measurements within 10 of each other might as well be the same.

 

[dmanb2b]

Absolutely agree...the other cause could be that perhaps you had some evaporation since your last CYA test...so your CYA concentration may be slightly higher...although if you have an autofil, you can throw that theory out the window :lol:

Anyways, I always view the CYA test as a +/-10ppm measure...cracks me up when someone reports CYA of lets say 47 ...I get all cross eyed everytime I do that test, staring at that darn dot.

 

[imcj]

Ha! Thanks everybody. That makes me feel better.