Dealing with algae in your pool can be frustrating and time-consuming, but with the right strategies, you can get rid of it quickly and ensure it never comes back. Black algae, also known as blue-green algae, can be particularly challenging to remove due to its ability to root into pool surfaces. Algae growth not only makes your pool water unappealing but can also lead to safety hazards, clogged filters, and bacterial contamination.
This comprehensive guide will help you understand why algae grows, how to treat it effectively, and how to prevent it from returning, ensuring a clean, sparkling, and safe swimming pool year-round.
What is Pool Algae and Why Does It Grow?
Algae are tiny aquatic organisms that thrive in water, particularly when nutrient levels (like nitrates and phosphates) are high. While algae are not inherently dangerous, they can disrupt your pool’s health by providing a breeding ground for harmful bacteria and other pathogens, and can also damage the pool’s surfaces.
Algae spores can enter your pool through:
- Wind and Rain: Algae spores are naturally airborne.
- Swimwear and Toys: Algae can latch onto items used in lakes or untreated pools.
- Plant Debris and Soil: Blown-in leaves, dust, or dirt often introduce spores.
Ideal Algae Conditions:
- Low Chlorine Levels: When chlorine drops below 2 ppm, algae grow rapidly.
- Poor Filtration and Circulation: Stagnant water allows spores to settle and multiply.
- Warm Temperatures: Algae thrive in temperatures above 25°C.
- Sunlight Exposure: Sunlight encourages algae blooms, particularly green algae.
Causes of Pool Algae
Pool algae can be caused by a variety of factors, including imbalanced pool water chemistry, poor pool maintenance, and environmental conditions. Understanding these causes can help you take proactive steps to prevent algae growth and keep your pool water clear and inviting.
Imbalanced Pool Water Chemistry
Imbalanced pool water chemistry is one of the most common causes of pool algae. When the pH, alkalinity, and calcium hardness levels in the pool water are not within the recommended ranges, it can create an environment that is conducive to algae growth. For example, if the pH level is too high or too low, it can affect the effectiveness of the chlorine in the pool, allowing algae to grow. Similarly, if the alkalinity level is too low, it can cause the pH level to fluctuate, creating an environment that is ideal for algae growth. Regularly testing and adjusting your pool’s water chemistry is crucial to prevent algae from taking hold and damaging the pool’s surfaces.
Poor Pool Maintenance
Poor pool maintenance is one of the primary causes of algae growth in pools. When pool owners neglect regular cleaning and upkeep, it can lead to an imbalance in the pool’s chemistry, creating an ideal environment for algae to thrive. This includes failing to check and adjust chlorine levels, neglecting to clean the pool filter, and not running the pool pump regularly. Without these essential maintenance tasks, a green pool can quickly become a reality, as algae and potentially harmful bacteria take hold. Regularly skimming the pool surface, brushing the walls, and ensuring proper filtration are key steps in preventing algae growth and maintaining a healthy swimming environment.
The 3 Common Types of Pool Algae
Identifying the type of algae in your pool is critical for effective treatment. Here’s how to recognise and treat each type:
1. Green Algae
- Appearance: Slimy green spots or cloudy water that quickly worsens.
- Cause: Poor circulation, low chlorine levels, and warm water.
- Impact: Green algae can cover surfaces and turn your pool into a green pool with murky water within days.
Treatment for Green Algae:
- Brush the Pool Thoroughly: Use a stiff pool brush to loosen algae on walls, steps, and floors.
- Shock the Pool: Double the chlorine shock dose (e.g., 2.5–3 kg of shock for 40,000 litres).
- Vacuum to Waste: Use the “waste” setting to remove algae debris without recirculating it.
- Filter Continuously: Run the pump for 12–24 hours until water clears.
- Add Algaecide: Use a non-foaming algaecide for extra protection.
2. Yellow (Mustard) Algae
- Appearance: Yellow-brown powdery spots that form in shaded areas like pool corners.
- Cause: Chlorine-resistant spores thrive in humid, low-light conditions.
- Impact: Yellow algae can survive outside the pool, contaminating swimwear, filters, and cleaning tools.
Treatment for Yellow Algae:
- Brush the Affected Areas: Focus on shaded corners, steps, and crevices.
- Triple Shock the Pool: Use 1.5 kg of shock per 40,000 litres of water. Apply shock at night for maximum effectiveness.
- Disinfect Pool Accessories: Clean toys, floats, swimsuits, and brushes to prevent reinfection.
- Run the Filter Continuously: Allow the pump to run for at least 48 hours.
- Apply a Phosphate Remover: Starve algae by removing its nutrient supply.
3. Black Algae
- Appearance: Small black spots with rough, raised edges, deeply rooted into grout and tile.
- Cause: Cyanobacteria anchor into porous surfaces, making them resistant to chemicals.
- Impact: Black algae are the toughest to eliminate and require persistent treatments.
Treatment for Black Algae:
- Scrub Aggressively: Use a stainless steel brush to break the algae’s protective layer.
- Apply Algaecide Directly: Spot-treat black algae with concentrated algaecide.
- Quadruple Shock the Pool: Use 4x the regular shock dose to penetrate deep roots.
- Repeat Scrubbing and Shocking Daily: Persistence is key to eradicating black algae.
- Clean Filters and Equipment: Replace filters if necessary to prevent reinfection.
Step-by-Step Guide: How to Remove Pool Algae
1. Test and Balance Water Chemistry
Before treatment, make sure to test your pool’s water to ensure proper balance and protect the pool’s surfaces:
- Chlorine: 2–4 ppm
- pH: 7.2–7.6 (low pH improves chlorine efficiency)
- Cyanuric Acid: 30–50 ppm
Adjust levels as necessary for optimal shock treatment results.
2. Brush the Pool Surfaces
Use a pool brush to vigorously scrub walls, steps, floors, and other surfaces. Pay close attention to corners and shaded areas where algae hide.
3. Shock the Pool
Use calcium hypochlorite shock (granular chlorine) to shock your pool for best results.
Follow dosage guidelines:
- Green Algae: Double shock dose.
- Yellow Algae: Triple shock dose.
- Black Algae: Quadruple shock dose.
Pro Tip: Shock the pool at night to prevent chlorine breakdown from sunlight.
4. Vacuum to Waste
Vacuum the pool using the “waste” setting to remove dislodged algae and debris. Top up the water as needed after vacuuming.
5. Run the Pool Filter
Run the pump continuously for 12–48 hours to circulate the water and remove algae particles. Clean or backwash the filter regularly during this process.
6. Add Algaecide and Phosphate Remover
After shocking, add a quality algaecide to kill any remaining spores. Follow up with a phosphate remover to prevent future algae blooms.
Additional Tips for Effective Algae Removal
In addition to using algaecides and other chemicals to remove algae from your pool, there are several other tips that can help to ensure effective algae removal. These methods can enhance the effectiveness of chemical treatments and help maintain a clean, algae-free pool, protecting the pool’s surfaces from damage.
Circulating the Pool Water
Circulating the pool water is an important step in removing algae from your pool. When the pool water is circulated, it helps to distribute the algaecides and other chemicals evenly throughout the pool, ensuring that all areas of the pool are treated. Additionally, circulating the pool water helps to remove any dead algae and debris that may have accumulated on the pool floor and walls. To circulate the pool water, simply turn on the pool pump and let it run for several hours. You can also use a pool skimmer to remove any debris that may have accumulated on the surface of the water.
By following these tips and using the right chemicals, you can effectively remove algae from your pool and keep it clean and safe for swimming. Remember to always follow the manufacturer’s instructions when using any chemicals, and take necessary safety precautions to avoid exposure.
Backwashing the Filter
Backwashing the filter is an essential part of regular pool maintenance. This process involves reversing the flow of water through the filter to remove dirt, debris, and algae that have accumulated on the filter media. By backwashing the filter regularly, you ensure that it operates efficiently, preventing algae and bacteria from growing in the pool water. A clean filter is crucial for maintaining clear, algae-free water. Make it a habit to backwash your filter according to the manufacturer’s recommendations, especially after heavy pool use or following an algae treatment, to keep your pool water clean and safe for swimming.
Preventing Algae Growth in Pools
Prevention is the best approach to keeping your pool algae-free. Follow these essential tips:
- Maintain Chlorine Levels: Keep chlorine between 2–4 ppm.
- Test Water Weekly: Use a reliable test kit to monitor pH, alkalinity, and chlorine.
- Run Your Pump Regularly: Ensure at least 8–12 hours of circulation daily.
- Clean Filters Frequently: Backwash sand filters and clean cartridge filters to improve filtration.
- Brush and Vacuum Weekly: Routine brushing prevents algae from taking hold.
- Use Algaecide Weekly: Preventative treatments stop algae growth before it starts.
- Remove Debris: Skim leaves, dirt, and dust regularly to eliminate nutrients.
- Use a Pool Cover: Reduce sunlight and debris when the pool is not in use.
Regular Pool Maintenance
Regular pool maintenance is crucial to preventing algae growth and keeping your pool water clean and safe for swimming. This includes tasks such as checking and adjusting chlorine levels, cleaning the pool filter, running the pool pump regularly, and skimming the pool surface to remove debris. By performing these tasks consistently, pool owners can help to prevent algae growth and ensure that their pool water remains clear and inviting. Regular maintenance not only keeps algae at bay but also extends the life of your pool equipment and enhances the overall swimming experience.
Can You Swim in a Pool with Algae?
Swimming in a pool with algae is not advised. Here’s why:
- Health Risks: Algae can harbour harmful bacteria like E. coli, leading to skin rashes, eye infections, and stomach issues.
- Slippery Surfaces: Algae-covered surfaces increase the risk of falls and injuries.
- Poor Visibility: Murky water reduces visibility, making it harder to spot swimmers in distress.
How Long Does It Take to Remove Algae?
- Green Algae: 24–48 hours with proper shock and brushing.
- Yellow Algae: 3–5 days with aggressive treatment and phosphate removal.
- Black Algae: Up to 7+ days due to its deep roots and resistance to chlorine.
Note: The time it takes to get rid of algae depends on the type of algae, the pool size, surface type, and the severity of the infestation.
Fibreglass Pools vs Concrete Pools
- Fibreglass Pools: Nonporous surfaces make it harder for algae to attach, simplifying removal.
- Concrete Pools: Porous surfaces allow algae roots to anchor deeply, requiring more intensive treatments.
When to Call a Professional
If algae persist despite treatment, it’s time to contact a professional pool service. Experts can:
- Drain and Acid-Wash: Remove deep stains and algae colonies.
- Inspect Filtration Systems: Identify circulation issues contributing to algae growth.
- Offer Long-Term Solutions: Resurfacing or professional-grade algaecides for stubborn infestations.
Safety Precautions
When dealing with algae in your pool, it’s essential to take safety precautions to avoid exposure to harmful bacteria and other contaminants. Here are some safety precautions to keep in mind:
Avoiding Swimming in Algae-Infested Pools
Avoid swimming in pools that are infested with algae, as it can pose serious health risks. Algae can harbor harmful bacteria, such as E. coli, parasites, and salmonella, which can cause a range of health problems, including skin infections, respiratory issues, and gastrointestinal problems. If you notice algae growth in your pool, it’s essential to take immediate action to remove it and restore the pool’s chemistry to a safe and healthy level. Always ensure the pool is clear and the water chemistry is balanced before allowing anyone to swim.
Final Algae Prevention Checklist
☑ Maintain chlorine levels: 2–4 ppm
☑ Run your pump: 8–12 hours daily
☑ Brush and vacuum weekly
☑ Test and balance water chemistry weekly
☑ Backwash and clean filters regularly
☑ Use algaecide and phosphate removers
☑ Remove debris and cover the pool when not in use
Conclusion
Algae growth in your pool can turn a relaxing swim into a frustrating chore, but with the right approach, it is entirely manageable. By understanding the different types of algae—green, yellow, and black—you can tailor your treatment strategy to address the issue quickly and effectively. The key to success lies in a combination of regular pool maintenance, balanced water chemistry, and consistent filtration and circulation.
Prevention is always better than cure. Maintaining chlorine levels, brushing and vacuuming weekly, using algaecides, and eliminating nutrient sources like phosphates will significantly reduce the chances of algae blooms. For particularly stubborn algae, such as black algae, persistence and professional intervention may be necessary.
By following this comprehensive guide, you can eliminate algae, restore your pool’s clarity, and ensure a safe, inviting swimming environment. A clean, algae-free pool not only looks beautiful but also enhances the swimming experience for you and your family. With consistent care and attention, you can enjoy a sparkling pool all year round.
Take control of your pool’s health today and say goodbye to algae for good by contacting 1Poolcare for the best green pool cleaning services in Perth!