I have been testing CYA in my pool for a year and a half. I'm doing a pretty good job of it. I thought it would be a good ideal to buy the CYA standard solution R-7065, just to check my calibration eye.
I just received my R-7065 and R-0013 8oz. each today.
One was labeled R=7065, but the other was not labeled. Both was sealed, I'm assuming they forgot to put the R-0013 label on the bottle.
No big deal, but when I tested the solution (15ml R-0013 & 15ml R-7065), Speed stir, rest for 30 sec, then speed stir.
Behold I indicate 30ppm not 50. There is another thread talking about this, and I'm getting the same result.
I don't use the small bottle with red cap, the bottom of label is 15ml and top of label is 30ml. So I just use the measurement container and it works for me.
1) TFTestkits is closed right now, because its 1900 here in TX. But I wonder if the bottle that is not label really is R-0013?
2) And am I doing the CYA test correct, I have two CYA tester tubes, and they both indicate 30 when the black dot goes away?
BTW, test results from today