Is Algae Possible? CC=0

[PoolDoc]

The quick test for iron stains is a handful of Vitamin C tabs on a stained area for a few minutes. If the Vit. C lifts the stains, it's metal, probably iron.

[Shifty]

I have yet to try the vitamin C tabs on a stain; however, I was able to get my hands on the most recent water quality report for Philadelphia, PA.

Cl= 1.9-3.1 ppm
pH= 7.4 ppm
TA= 60 ppm
TH= 135 ppm
Lead= 90% of the water tested had less than 5.8 ppb
Copper= 90% of the water tested had less than .32 ppm

With those traces of lead and copper, is it possible to produce stains?

[PoolDoc]

0.32 ppm of copper could stain; the lead will not.