Why Is My Pool Still Green After Algaecide?

Using algaecide is a common method to combat algae in swimming pools, but sometimes the pool remains green even after treatment. Understanding why this happens can help you address the issue more effectively and restore your pool to its clear, inviting state.

Ⅰ. Common Reasons Your Pool Is Still Green After Algaecide

1. Insufficient Filtration:

Filter Issues: If your pool filter isn’t working correctly or is clogged, it won’t effectively remove dead algae and debris from the water.

Running Time: Ensure that the pool pump is running long enough each day. Ideally, it should run for 8-12 hours to circulate and filter the water properly.

2. Incorrect Chemical Balance:

pH Levels: If the pH level of your pool is too high or too low, it can reduce the effectiveness of chlorine and algaecides. Aim for a pH level between 7.2 and 7.6.

Alkalinity: Total alkalinity should be between 80 and 120 ppm to help stabilize pH levels.

Cyanuric Acid Levels: High levels of cyanuric acid (stabilizer) can bind with chlorine, making it less effective. Ensure that the cyanuric acid levels are between 30 and 50 ppm.

3. Inadequate Chlorine Levels:

Chlorine Demand: Sometimes, the chlorine demand is higher due to heavy contamination. Even after shocking, the chlorine might get used up quickly, leaving the pool vulnerable to algae.

Continuous Algae Growth: If the chlorine levels drop too quickly after shock treatment, algae can continue to grow. Consistently maintain chlorine levels between 1-3 ppm.

4. Organic Debris:

Leaves and Dirt: Organic matter like leaves, dirt, and debris provide nutrients for algae growth. Regularly clean the pool surface and vacuum the bottom to remove these sources.

Hidden Algae: Algae can hide in pool fixtures, behind ladders, or in other less accessible areas. Ensure all parts of the pool are thoroughly cleaned.

Ⅱ. Steps to Clear a Green Pool

1. Check and Adjust Chemical Levels:

Test Water: Use a reliable test kit to check the pH, alkalinity, chlorine, and cyanuric acid levels.

Adjust pH and Alkalinity: Use pH increaser or decreaser and alkalinity increaser to bring levels into the recommended range.

Shock Again if Needed: If chlorine levels are still low, perform another shock treatment. Follow the instructions carefully to ensure proper dosage.

2. Enhance Filtration and Circulation:

Clean the Filter: Backwash or clean your filter to ensure it is functioning optimally. Consider deep cleaning if it hasn’t been done in a while.

Run the Pump Longer: Increase the pump’s running time to ensure better water circulation. Running it continuously for 24-48 hours can help clear up the water.

3. Manual Cleaning:

Skim and Vacuum: Skim the surface to remove leaves and debris. Vacuum the pool floor to remove settled particles.

Brush the Pool: Brush the walls, floor, and other surfaces to dislodge algae. Pay special attention to hidden areas.

4. Use a Clarifier:

Add Pool Clarifier: A clarifier can help coagulate small particles, making it easier for the filter to capture them. This can speed up the process of clearing the water.

5. Maintain Proper Prevention Measures:

Regular Testing: Test your pool water at least once a week to keep chemical levels balanced.

Consistent Cleaning: Skim, brush, and vacuum your pool regularly to prevent algae buildup.

Use Algaecide Preventatively: Even when the water is clear, use algaecide as part of your regular maintenance routine to prevent algae from returning.

Ⅲ. How to Effectively Prevent a Green Pool

1.Use a Pool Cover:

When the pool is not in use, cover it to prevent debris and contaminants from entering. This reduces the organic matter that can feed algae growth.

2.Regular Algaecide Treatments:

Incorporate algaecides into your regular maintenance routine, even when no visible algae are present. Preventative use of algaecide helps stop algae from taking hold.

3.Manage Surrounding Vegetation:

Trim trees and bushes around the pool area to minimize the amount of leaves and pollen that can fall into the pool. This helps reduce the organic load in the water.

Ⅳ. Conclusion

A green pool can be a persistent problem, even after using algaecide. By understanding the underlying issues such as insufficient filtration, incorrect chemical balance, and environmental factors, you can take more effective steps to clear your pool. If your pool remains green despite your best efforts, consider consulting a pool professional to diagnose and address more complex issues.