How to Treat a Pool with High Phosphates

Use a phosphate remover to reduce phosphate levels, which help prevent algae growth. Try our AquaDoc Phosphate Remover.

What Are Phosphates and Why Are They a Problem for Pools?

Phosphates are chemical compounds that occur naturally in both fresh and saltwater. They come from many sources, such as leaves, debris, fertilizers, and even detergents. While phosphates are harmless in small quantities, high levels can lead to several issues, particularly an increase in algae growth. Algae thrives on phosphates, and once it has access to these nutrients, it can quickly multiply, turning your pool into a green, murky mess.

The presence of high phosphates in a pool doesn’t just lead to algae problems; it can also affect the overall water chemistry. For instance, high phosphate levels can disrupt the effectiveness of chlorine, making it harder to keep the water sanitized. This can create a constant battle to maintain clear, healthy pool water.

How to Test for High Phosphates

Before you can treat your pool for high phosphates, you need to confirm that they are indeed the problem. Testing for phosphates is simple and can be done with a phosphate test kit, which is available at most pool supply stores. These kits are easy to use and provide a clear reading of the phosphate concentration in your pool water.

Here’s a quick guide on how to test for phosphates:

1. Purchase a phosphate test kit: Make sure you get one that’s specifically designed for pools.

2. Collect a water sample: Follow the kit’s instructions on how to collect a sample from your pool.

3. Follow the testing procedure: Typically, the kit will involve adding a reagent to the water sample and comparing the color change to a chart.

4. Evaluate the results: The ideal phosphate level in your pool should be below 100 parts per billion (ppb). Anything above this suggests that your pool has high phosphate levels.

Steps to Treat High Phosphate Levels

Once you’ve confirmed that your pool has high phosphate levels, it’s time to take action. Here’s how you can treat the problem:

1. Remove organic debris

Leaves, twigs, and other organic material can be a major source of phosphates in your pool. To get rid of them, use a skimmer or pool net to remove debris from the water's surface. It’s also important to regularly clean your pool’s filter to ensure it’s not trapping debris that could break down and release more phosphates.

2. Use a phosphate remover

Phosphate removers are specialized chemicals designed to bind with phosphates in the water and remove them. They come in both liquid and granular forms, and once added to the pool, they will work to lower phosphate levels. Be sure to follow the instructions on the product’s label carefully.

3. Maintain proper water balance

Keeping your pool’s water balanced is crucial to preventing future phosphate problems. Regularly check the pH, alkalinity, and calcium hardness levels. Water that’s out of balance can encourage the growth of algae, making it harder to control phosphate levels. The pH should be between 7.2 and 7.6, and alkalinity should be in the range of 80-120 ppm.

4. Increase chlorine levels

While chlorine won’t directly remove phosphates, it can help prevent algae growth by maintaining a high enough level of sanitization. Make sure your pool’s chlorine levels are in the recommended range of 1-3 ppm. Adding chlorine to the pool regularly will help prevent algae from feeding on any remaining phosphates.

5. Regularly clean your pool

Frequent cleaning is one of the best ways to keep phosphates under control. Regularly vacuum the pool, skim the surface, and clean the filter to ensure that any leftover debris is removed. The more you clean, the less likely phosphates will have a chance to build up.

Preventing Future Phosphate Problems

Once you’ve successfully treated high phosphate levels in your pool, it’s important to prevent them from returning. Here are some tips to keep phosphates at bay:

1. Use phosphate-free pool chemicals

When purchasing pool chemicals like algaecides or cleaning agents, look for ones that are phosphate-free. This will help prevent further buildup in your pool.

2. Control the use of fertilizers

Fertilizers are a common source of phosphates. If you have plants or grass near your pool, be careful about the type and amount of fertilizer you use. Consider switching to a low-phosphate or phosphate-free fertilizer to reduce the risk of contamination.

3. Install a pool cover

A pool cover can help reduce the amount of debris that falls into the water, including organic material that can release phosphates. It also helps to keep the pool cleaner, requiring less maintenance in the long run.

4. Regularly test for phosphates

Keep an eye on phosphate levels by testing your pool water regularly. By monitoring the levels, you can catch any problems early and take action before they get out of hand.

5. Use a quality filtration system

A high-quality filtration system can help reduce the accumulation of phosphates in your pool. Make sure your filter is working efficiently and is appropriate for your pool size. Regular maintenance of the filter will ensure it continues to function properly, preventing the buildup of debris that could contribute to high phosphate levels.

6. Monitor water sources

Consider the water source you’re using to fill your pool. Well water, for example, may have higher phosphate levels than municipal water. If you notice consistent phosphate problems, testing the water source before filling your pool may reveal high phosphate concentrations, allowing you to take preventive measures beforehand.

7. Be mindful of pool chemicals

Certain pool chemicals, especially those used to treat algae and other contaminants, can contain phosphates. Always read the labels carefully when buying products for your pool. Opting for phosphate-free or low-phosphate options will help you maintain healthier pool water.

How Do You Know When It’s Time to Act?

Knowing when to take action can be difficult, but there are signs that your pool may be suffering from high phosphate levels:

• Green or cloudy water: If your pool water is turning green, even after adding chlorine, it’s a clear sign that algae is thriving due to excess nutrients like phosphates.

• Persistent algae growth: Algae blooms are more likely in pools with high phosphate levels. If your pool seems to always have algae issues despite regular cleaning and chlorine treatments, phosphates may be the culprit.

• Reduced chlorine effectiveness: If you’ve noticed that your chlorine isn’t working as well as it should, even after maintaining proper levels, phosphates might be interfering with its effectiveness.

By addressing these issues early, you can prevent further complications and keep your pool water sparkling clean.