3 Reasons to Try Vitamin C Before Draining a Pool

It’s the cheapest test for metal stains Crush a few vitamin C tablets, put them in a mesh bag or sock, and rub the stain. If it lightens or disappears within a minute, the stain is from copper, iron, or manganese—not organic matter.

Chlorine shock won’t fix metal stains Organic stains from leaves or algae usually fade with chlorine shock. If shock does nothing, you have metal stains. Vitamin C or ascorbic acid is the correct treatment.

Draining is expensive and risky Draining a pool costs money, risks liner damage, and often exposes new stains. Vitamin C is a five-dollar fix that almost always works on metal stains.