Table of Contents

How to Clean the Green Pool?

Turning a murky green swimming pool back into a sparkling oasis requires a multi-pronged approach focusing on killing algae, balancing the water chemistry, and removing dead organic matter. The process can be time-consuming, but with the right tools, chemicals, and patience, you can restore your pool to its former glory and enjoy swimming again.

Understanding the Green Monster: Why Pools Turn Green

A green pool is almost always caused by an algae bloom. Algae are microscopic plant-like organisms that thrive in warm, nutrient-rich water. Several factors contribute to algae growth:

Lack of proper sanitation: Insufficient chlorine or other sanitizers allows algae to flourish.
Poor circulation: Stagnant water creates pockets where algae can easily grow.
Incorrect water chemistry: Imbalances in pH, alkalinity, and calcium hardness can make the pool water hospitable to algae.
Phosphates: Phosphates are a food source for algae, often introduced through tap water, fertilizers, and decaying organic matter.
Sunlight: Sunlight provides the energy algae need to grow.

The 5-Step Approach to Crystal Clear Water

Cleaning a green pool effectively involves a systematic approach:

Step 1: Test and Balance the Water

Before doing anything else, test your pool water using a reliable test kit or strips. Pay close attention to the following parameters:

pH: Aim for a range of 7.2 to 7.8.
Alkalinity: Aim for a range of 80 to 120 ppm (parts per million).
Calcium Hardness: Aim for a range of 200 to 400 ppm.
Cyanuric Acid (Stabilizer): Aim for a range of 30 to 50 ppm.

Adjust the water chemistry accordingly, following the instructions on your pool chemicals. Correcting these imbalances is crucial for the subsequent steps to be effective. Use pH increaser/decreaser, alkalinity increaser/decreaser, and calcium hardness increaser as needed.

Step 2: Shock the Pool

Shocking the pool involves adding a large dose of chlorine to kill the algae. Use a chlorine shock specifically designed for swimming pools. For a severe algae bloom, you may need to “triple shock” the pool, meaning you’ll use three times the normal amount of shock. Add the shock late in the evening or at night to minimize its degradation by sunlight. Never add different pool chemicals together. Always add chemicals separately, allowing sufficient time (usually several hours) between additions.

Step 3: Brush, Brush, Brush

Algae cling to pool surfaces, so thorough brushing is essential. Use a pool brush to scrub the walls, floor, steps, and any other areas where algae are visible. This will help dislodge the algae and allow the chlorine to reach them more effectively. Brush vigorously, paying particular attention to corners and crevices.

Step 4: Vacuum the Pool

After shocking and brushing, the dead algae will settle to the bottom of the pool. Vacuum the pool thoroughly to remove this debris. If you have a sand filter, vacuum to waste to prevent clogging the filter. If you have a cartridge or DE filter, you may need to clean the filter more frequently during this process.

Step 5: Filter, Filter, Filter

Run your pool filter continuously for 24-48 hours to remove any remaining dead algae and debris. Backwash your sand filter regularly, or clean your cartridge or DE filter as needed. Monitor the water clarity and repeat steps 2-4 if necessary. Proper filtration is key to achieving crystal clear water.

Beyond the Basics: Preventing Future Blooms

Once your pool is clean, it’s crucial to implement preventative measures to avoid future algae blooms:

Maintain proper sanitation: Regularly test and adjust your chlorine levels. Consider using a pool sanitizer system like a salt chlorine generator or UV system.
Ensure proper circulation: Run your pool pump for at least 8 hours per day, or more if needed.
Balance water chemistry: Test and adjust your water chemistry weekly.
Use algaecide: Use a preventative algaecide regularly, especially during hot weather.
Remove phosphates: Use a phosphate remover if your pool water has high phosphate levels.
Clean your pool regularly: Brush and vacuum your pool weekly to prevent algae buildup.
Keep your pool covered when not in use: A pool cover can help reduce sunlight and prevent debris from entering the pool.

Frequently Asked Questions (FAQs)

FAQ 1: How long does it take to clean a green pool?

The time it takes to clean a green pool depends on the severity of the algae bloom. Mild cases might take 2-3 days, while severe cases can take a week or longer. Patience is key during this process.

FAQ 2: What type of shock should I use?

Calcium hypochlorite (Cal Hypo) is a powerful shock option, especially for severe algae blooms. Dichlor is a stabilized shock that’s effective but can increase cyanuric acid levels. Non-chlorine shock (potassium monopersulfate) oxidizes organic matter but doesn’t kill algae, so it’s best used as a supplement to chlorine shock.

FAQ 3: Can I swim in a green pool?

Swimming in a green pool is generally not recommended. The algae can irritate the skin and eyes, and the water may contain harmful bacteria. It’s best to wait until the pool is clean and the water chemistry is balanced before swimming.

FAQ 4: What is black algae, and how do I get rid of it?

Black algae is a stubborn type of algae that forms dark, raised spots on pool surfaces. It’s resistant to chlorine and requires special treatment. Scrub the affected areas with a wire brush, then apply a specialized black algae algaecide. Repeat the process as needed.

FAQ 5: How do I prevent phosphates from causing algae blooms?

Use a phosphate remover regularly to reduce phosphate levels in your pool water. Also, avoid using phosphate-based fertilizers near the pool.

FAQ 6: How often should I test my pool water?

Test your pool water at least once a week, or more frequently during periods of heavy use or hot weather.

FAQ 7: Can I use household bleach to shock my pool?

While household bleach (sodium hypochlorite) can be used as a chlorine source, it’s generally not recommended for shocking a pool due to its lower concentration and potential for adding unnecessary byproducts. Pool-specific shock is usually more effective and easier to manage.

FAQ 8: Why is my pool still green after shocking it?

There are several reasons why your pool might still be green after shocking it:

Insufficient shock: You may need to shock the pool again with a higher dose of chlorine.
High phosphate levels: Phosphates can neutralize the chlorine.
Poor circulation: The chlorine isn’t reaching all areas of the pool.
Inadequate filtration: The filter isn’t removing the dead algae quickly enough.
The algae is resistant: Some algae strains are more resistant to chlorine. Try using a different type of algaecide.

FAQ 9: What is the ideal pH level for a swimming pool?

The ideal pH level for a swimming pool is between 7.2 and 7.8. This range is comfortable for swimmers and allows chlorine to be most effective.

FAQ 10: How do I know if my pool filter is working properly?

Check the pressure gauge on your filter. If the pressure is significantly higher than normal, it’s likely time to backwash your sand filter or clean your cartridge or DE filter. Also, visually inspect the water returning to the pool for clarity. Cloudy water indicates a problem with filtration.

FAQ 11: Can I use a pool cover to prevent algae growth?

Yes, a pool cover can help prevent algae growth by blocking sunlight and reducing evaporation. Solid covers are more effective than mesh covers for this purpose.

FAQ 12: When should I call a pool professional?

If you’ve tried the above steps and your pool is still green, or if you’re uncomfortable handling pool chemicals, it’s best to call a qualified pool professional. They can diagnose the problem and recommend the appropriate solution. They have specialized equipment and knowledge to tackle complex pool issues.