Calcium hardness test starts out purple

[Black Diamond]

So, I am aware of the calcium fading endpoint issue when testing CH using a Taylor K-2006 kit, but my tests start out purplish, not red, and finish blue. Is that an indication of small traces of copper or iron as well? If so, should I be concerned?

Thanks,
Greg

 

[PoolStored]

What is your FC?

 

[JoyfulNoise]

What is your CH? Post a full set of test results s

 

[Black Diamond]

pH: 7.5
FC: 4.5
CC: 0
TA: 75-80
CH: 210
CYA: 27-28

Thanks!

 

[mgtfp]

Doesn't look too unusual to me.

Here's a screenshot from the Taylor video:




And here the full video:

 

[Black Diamond]

Ahhh, okay, thank you for sharing photo. Looks in line with my color.

 

[JoyfulNoise]

At that low CH I would expect it to be purple. The indicator dye turns a deep red when calcium is present but is only pale blue when there is no hardness. So a purple color is predictable because the dye is added in excess of the amount needed to react with calcium so the color is always going to be a mixture of red and blue.