Most swimming pool stains occur when excess organic and/or metallic compounds meet unbalanced pool water. Incorrect pH, sanitizer, and alkalinity levels help set the stage for stain-causing debris and metals to wreak havoc on your home’s most valuable investment—your beautiful South Florida swimming pool!
Know the Source of Pool Stains
If not properly removed, decaying organic debris such as leaves, acorns, berries, and other materials can leave behind stains on the surface of your swimming pool. Organic debris typically leaves brown stains caused by naturally-occurring organic substances known as tannins.
Algae can speckle the surface of your swimming pool and leave a green tint to your pool water. The three most common types of algae are described by their respective colors—green, black, or yellow (also called mustard). Iron and copper metals are found naturally in pool water and their presence can be compounded by leaching from other sources such as residential plumbing, fertilizers, and pesticides. Copper also comes from pool heaters that often have copper heat exchangers, and from pool algaecides.
The problem with metals is that water evaporates but metal does not, so the concentration of metals builds up over time. When the saturation point is reached, pool water is unable to contain additional metal. This is when metals start to cleave to the surface of the swimming pool and leaves stains.
Identifying Pool Stains by Type
- Organic Stains: These will leave an impression in the shape of the offending debris, usually brown in color.
- Green Algae: Green-tinted pool water and speckled pool surface.
- Mustard Yellow Algae: Appropriately named for its brown and yellow color, this type of algae is defined by its wispy texture and grows in shady areas of the water.
- Black Algae: Forms black speckles and clusters that will grow roots into the surface of your swimming pool.
- Iron: Stains ranging from yellow, rust, to dark brown in color.
- Copper: This type of metal can tint pool water blue before stains form on the pool’s surface. These stains are commonly blue-green in color but can also appear gray, black, and brown. Copper stains can also appear purple in color when cyanuric acid levels are high.
- Manganese- Found in well water in some regions; this metal leaves a purple tint in the water with brown, black, or purple stains on the surface of the pool.
How to Test for Stains
For most pool owners, the most effective way to identify a pool stain is to use a stain kit. For iron stains, you can try a simple test using vitamin C. Place a vitamin C tablet against the stained area for about 30 seconds to see if the stain gets lighter or disappears. If so, you have iron stains and can use ascorbic acid to treat it accordingly. If not, you have at least ruled out iron as a potential suspect. Similarly, if you suspect a stain from leaves or other decomposed natural debris, hold a chlorine tablet on the stain to see if it lightens. Chlorine can lighten organic stains but will not help metal stains. Shocking the pool to raise free chlorine is an effective way to get rid of brown tannin stains.
Once you find a stain solution that works for you, follow up with the specific recommended treatment. Keep in mind that it might take repeated treatments to achieve a stain-free pool, so don’t worry! Consistency is key, and your pool water and surface area will be spot-free and sparkling in no time.
Keep Your Pool Clean and Beautiful with Residential and Commercial Pool Maintenance by Horizon Pool and Patio
Worried about stains? Not sure where to start? We’ve got you covered. The experts at Horizon Pool and Patio are standing by to help with your residential and commercial swimming pool needs. From scheduled maintenance services to providing you with cost-effective and easy maintenance solutions, our team is ready to help breathe new life in your beautiful South Florida swimming pool. Ready to get started? A stain-free pool is only a phone call away. Contact Horizon Pool and Patio today at (561) 790-0665 for more information.