CYA test with R-7065 standardized solution - Huh?

[viking68]

So, I got (by my own mistake) the R-7065 CYA 50ppm standardized solution on a re-order. Ok - gives me a baseline to show what CYA test should look like for 50ppm. Waited until new R-0013 arrived, performed test.

This is all fresh stuff from TF Test Kits. (Rebecca is 'da bomb!)

Problem is - I put the R-7065 in the mix bottle, add R-0013 to the top, shake rattle and roll, 30 seconds later - run test. (Have done this now 3 times - 30 seconds, 1 minute and 5 minute waits - all tests the same result.)

Wow! At 50, black dot is visible. Doesn't disappear until almost 20.

This test has always confounded me as it's so subjective. I've read tons on here about this test, back to the sun, side shadow, upside down under full moon, well, you get the drift.

On pool water test, I'm reading (back to sun) 35ppm.

Or, am I? Anybody have any suggestions? Am I doing something wrong?

Again, everything from TF Test Kits.

 

[Shekkie]

I thought the 50 ppm solution was premixed......meaning you just pour that straight in the tube without any r-7065 mixed in. I may be wrong of course but give that a shot.

 

[NeedMoreSun]

The instructions say to use it in place of the pool water and still add the R-0013.

 

[viking68]

The instructions say to use it in place of the pool water and still add the R-0013.

Which, is what I did.

 

[ping]

You need equal parts R-7065 and R-0013. If you are filling the mixing bottle to the top you are not mixing the correct amount of reagents together. I like to mix them in a separate vial to make sure I have equal parts of reagents.

 

[Schadenfreude]

You have to shake it up very well just before you pour it in the viewing tube and you have to be in sunlight, with your back to the sun.

 

[viking68]

You need equal parts R-7065 and R-0013. If you are filling the mixing bottle to the top you are not mixing the correct amount of reagents together. I like to mix them in a separate vial to make sure I have equal parts of reagents.

Makes sense - I was just doing it like the normal CYA test in the bottle. I'll try it your way when the sun comes up tomorrow.