Metal Stains In Your Swimming Pool: What They Are And How To Get Rid Of Them

How to Combat Metal Stains in Your Pool

One ongoing challenge in pool care is managing metal stains, which often appear after high pH levels or chlorination. These stains are different from organic stains, which are caused by algae or environmental debris.

Fiberglass pools are particularly prone to metal stains, with iron being the most common culprit, especially in rural areas. If your pool water comes from a well, it’s important to test it for iron. To treat iron stains, try using Vitamin C or ascorbic acid. Simply place a Vitamin C tablet on the stain for 30 seconds—if it’s effective, continue treating with ascorbic acid. If stains persist, you may need to consider having iron-free water delivered to your pool.

Copper is another common cause of metal stains, often introduced through algaecides, mineral systems, or ionizers. Copper can also enter the water if the pH drops below 7.0, especially through copper heat exchange coils in pool heaters. In some cases, copper can turn blonde hair green. Rarely, metals can cause the water to turn green, blue, or yellow, but the water will remain clear—foggy water suggests other issues.

Removing metals from pool water can be challenging. The most effective solution is replacing the water with metal-free water, though this can be costly. More affordable options include regular maintenance and chemical adjustments. Lowering the pH and adding a sequestrant can help if your water changes color.

For long-term prevention, consider using a sequestrant. These chemicals bind to metals, preventing stains by breaking them down in the water. The most effective sequestrants contain HEDP, phosphonic acid, or phosphonic acid derivatives. Regularly dosing your pool with a sequestrant can help keep your water and surfaces metal-free.

We here to help you fight against metal stains in your swimming pool. We offer an array of products to help prevent and rid your pool of metal stains, including:

1. Pool Protect All

2. pH Down

3. Saline Protect All