Newbie help: TFP test kit FC differences

[Hartlimp]

Hi. New to this testing method. I need help making sure I understand the two test options for chlorine measurement. 1. The small gauge that has one side chlorine and the other ph- I measure the chlorine as instructed with adding drops and the yellow always appears darker than the highest reading. So I move to the larger chlorine 10ml and powder test. I add the drops and count them and then multiply 0.5 and it comes out as like 3 or 4. But shouldn’t this show up on the other test as within that window since it’s not actually showing higher than the scale reads?

 

[Bperry]

Hi. New to this testing method. I need help making sure I understand the two test options for chlorine measurement. 1. The small gauge that has one side chlorine and the other ph- I measure the chlorine as instructed with adding drops and the yellow always appears darker than the highest reading. So I move to the larger chlorine 10ml and powder test. I add the drops and count them and then multiply 0.5 and it comes out as like 3 or 4. But shouldn’t this show up on the other test as within that window since it’s not actually showing higher than the scale reads?

The yellow OTO testing isn’t very precise, don’t use it for anything except for knowing there’s chlorine or not. Use the powder FAS-DPD for accurate measurements.

 

[Donldson]

The OTO test measures Total Chlorine, FC + CC. Did you follow up your FAS-DPD FC test with the CC test?

And welcome to TFP!