Quck answer
Purple stains in a swimming pool can be caused by various factors, such as metals in the water, algae growth, or chemical imbalances. To get rid of these stains, follow these steps:
1. Identify the cause: Test the water for metal content and pH levels to determine the underlying issue causing the stains.
2. Adjust the pH levels: If the pH is too low or too high, balance it using appropriate chemicals to prevent further staining.
3. Remove metals: Use a metal sequestrant or stain remover specifically designed for swimming pools to eliminate metal deposits.
4. Brush and vacuum: Scrub the stained areas with a pool brush and vacuum the pool to remove any loose debris or algae.
5. Shock the pool: Shock the pool with a high dose of chlorine to kill any remaining algae or bacteria.
6. Maintain proper water chemistry: Regularly test and maintain the pool’s chemical balance to prevent future staining.
By following these steps, you can effectively get rid of purple stains and ensure a clean and clear swimming pool.
One of the most visually appealing issues that can arise with your swimming pool is the presence of purple stains. When pool owners open their pools in the spring, they often find beautiful lavender crystals clinging to the walls and equipment. These stains are caused by a chemical called cyanuric acid (CYA).
Cyanuric acid is formed when high levels of chlorine react with copper in the pool water. No matter how diligently you scrub and clean, the problem cannot be solved. Instead, the pool needs to be treated chemically and the CYA crystals will dissolve back into the water over time.
Treating the Correct Issue
When you notice purple crystals staining your pool, it is important to understand what does and does not cause them so that you can address the correct problem. A common misconception is that purple stains indicate the presence of algae. However, this is not true. Ironically, it is often low-quality algicides that introduce copper into the pool water, causing CYA. Therefore, treating for algae will not eliminate a CYA problem.
People also frequently mistake a CYA problem for a manganese problem. Manganese does indeed create a purple discoloration, but it affects the water itself, turning it purple. To resolve a manganese problem, the pool needs to be super chlorinated and the settled manganese particles vacuumed from the bottom of the pool.
Reducing CYA Levels Quickly
In the aquarium industry, fish keepers often say that “dilution is the solution.” This same principle can help resolve high CYA levels. By draining about half of your pool and then refilling it, you automatically reduce your CYA levels by half. This assumes, of course, that the water source does not contain copper.
After refilling the pool, allow the water to circulate for 48 hours. Then, check the CYA levels, ideally falling between 40 and 50 ppm. If they are not within this range, add a CYA reducing agent from a local pool supply store according to the product instructions.
Maintain pH Levels
Once you have achieved your desired CYA levels, it is important to maintain them by adjusting the pH and total alkalinity levels. Aim for a pH level between 7.4 and 7.6 and a total alkalinity of 80 to 140 ppm. Excessive pH levels above 7.8, total alkalinity above 150 ppm, and CYA levels above 100 ppm all contribute to CYA staining. Therefore, it is crucial to keep these numbers in check.
Once your pool has been properly treated and balanced, your task is to maintain these conditions. If you do so, the CYA stains will eventually dissolve on their own. This process typically takes around four weeks, during which it is safe to swim in the pool.
Addressing Persistent Copper Issues
CYA stains in your pool may be a one-time problem caused by a low-quality algicide. If you suspect this is the case, use higher-quality algicides in the future. However, it is also possible that there is copper in your water supply or copper pipe fittings in your plumbing. In such cases, ongoing treatment for copper in the pool is necessary.
To address this, treat the pool with a metal sequestering agent. Typically, this treatment is required once a week, but you can test your pool water to determine the appropriate timeline. The goal is to keep any copper in the pool water below 0.5 ppm.
