Absorbic Acid Turns Stain Darker

[tomintampa]

I have staining in my gunite pool. Exactly along the path where I pour my liquid chlorine. Read where chlorine could react with copper from copper based algaecides (which I used) to create staining.

So I crushed some Vitamin C tablets and put on a small area of the stain. Very quickly that area turned much darker/blacker almost like someone spilled copy machine toner on that spot.

Is that a normal reaction with using absorbic acid on a metal stain? Or could it be something else?

Thanks

[sktn77a]

Copper based algecides can produce blue/grey stains that turn darker (oxidise) on exposure to chlorine. Ascorbic acid doesn't usually cause brown water and worsening of the staining (?)