How to Properly Test CYA

[jobondur]

I'm having some issues testing CYA with my new TF-100 test kit (first time using). Am I looking for the dot to completely disappear (i.e. no trace of a dot no matter how faint) or am I looking for the dot to change to a lighter shade of gray?

My other test results are:
Salt - 2430
FC - 4.5
CC - 0.5
TC - 5.0
TA - 130
CH - 150
CYA - ~23 if you wait until you can't see any trace of the dot

 

[jblizzle]

Completely gone.

See extended-test-kit-directions-t25081.html#p206397

 

[jobondur]

Completely gone.

See extended-test-kit-directions-t25081.html#p206397

Thanks - I figured detailed directions were on here, just didn't quite know where to look.

 

[Richard320]

Bright light is essential. I bought a bottle of the standard solution to check myself, and I'm right on if it's full sunlight and I only hold the tube with my thumb and one finger. Yes, even shading it with all your fingers will make it read different. Plus I take several readings; same solution, just pour it back in the mixing bottle, give it a shake, and repeat.