How Do I Remove Pool Stains and Scale?

Quick answer: Identify the problem first. Rub a vitamin C tablet on a small spot: if the stain brightens it is likely metal, and if not it is likely organic. White crusty deposits are usually scale.

What to do

• Metal stains: use a stain remover and a metal sequestrant as labeled, then keep the water balanced
• Organic stains such as leaves: brush and shock
• Scale: lower pH and alkalinity into range, and use a scale remover for your surface
• If calcium is far above about 400 ppm, a partial drain and refill helps

How to prevent them

• Keep pH, alkalinity, and calcium in range
• Test your fill water for metals

When to call a pro

Heavy scale, stubborn stains, or surface damage should be handled by a pro who knows your pool finish.