Proper way to mix CYA reagent (R-0013)?

[bmann71]

Reason I ask is because I was testing a pool this weekend and if I swirled the small bottle I would get a reading of < 30ppm. Tried two separate tests (i.e. new reagent each time) and they both came back the same. I then redid the test but my son shook the bottle like you would a mixed drink and it came back with a reading > 40. Again I did it that way twice and both times were the same.

I have the K-2006 test kit by the way.

This happened by accident. I wasn’t trying to see which is correct. My 8 year old son just wanted to help and not telling him how to mix he just did it his way and thus the different readings.

So, do you swirl or shake the bottle for 30 seconds for an accurate test?

thanks.

 

[Richard320]

I measure out the reagents and let the speedstir mix it.

I also take multiple readings with the same sample, shaking it a couple times after I pour it back in the mixing bottle.

 

[bmann71]

I measure out the reagents and let the speedstir mix it.

I also take multiple readings with the same sample, shaking it a couple times after I pour it back in the mixing bottle.

Now why didn't I think of that. I just got the speedstir last week but didn't think to use it for that.

I also take multiple readings but I got a much higher reading when I shook it that's where my confusion started.

 

[Patrick_B]

It isnt the mixing method. This test has some variance even when run perfectly. All turbidity tests do when results are viewed with the eye. Light, distance, and sample measuring would give different results. Having run hundreds of boiler polymer target tests over the years, I can swear by this. No worries though it is more than precise enough.