CH Test for Metal Testing

[PoolStudent]

I just saw this video online, Video and it says you can use the CH test to get an idea of there is metal is the water. A blue color means less metal than a purple color. How true is this?

 

[chem geek]

It's true with regard to the fading endpoint where the change in color will revert back, but I didn't know it would also affect the color. Though that may be true, it's not quantitative since it doesn't tell you the quantity of metals nor their type (i.e. iron vs. copper).

That video also shows CuLator working though it's not clear that the other products (sequestrant) may also be affecting the test results and we've had very mixed results with CuLator being reported.