Alkilinty yellow

hazellief · Postby **hazellief** » Sun 22 May, 2011 10:06

testing alkilinty it only turns yellow still at 20 ppm when I test at 10ml it takes 4 drops x 25 is 100ppm but when i use 25ml it only turns yellow even after 25 or more drops.

Postby **chem geek** » Sun 22 May, 2011 13:40

If you are using a proper test kit, such as theTaylor K-2006 or the TFTestkits TF-100, then the Total Alkalinity (TA) test goes from green to red. At very high Free Chlorine (FC) levels, it may instead go from blue to yellow. If you are referring to this blue-to-yellow transition, then use more thiosulfate drops (R-0007) at the start of the test.