Hot Tub

[herbjoan]

water turned red when testing for chlorine level...ph okay.......help

[chem geek]

What kind of chlorine test are you using? If it's a DPD test, it is supposed to turn pink/red when you add the 5 drops of indicator and the intensity of it determines how much chlorine you have. If it's a FAS-DPD test, then the initial DPD powder turns the sample pink/red and you then count the titrating FAS drops to determine the amount of chlorine. If it's an OTO test, then the sample will turn yellow and the intensity of color determines how much chlorine you have. If the chlorine level is extremely high (>> 10 ppm FC) in the OTO test, then it can look orange instead of yellow.

Richard