How to Treat Mustard Algae in a Pool?
Mustard algae requires a more aggressive approach than typical green algae; successful treatment involves thoroughly brushing all pool surfaces, shocking the pool with significantly higher than normal chlorine levels, and using an algaecide specifically designed for mustard algae.
Understanding the Mustard Menace
Mustard algae, sometimes mistakenly called yellow algae, isn’t actually algae. It’s a type of bacteria that resembles algae and thrives in swimming pool environments. Unlike green algae, mustard algae is chlorine-resistant and often clings stubbornly to pool surfaces, especially in shady areas. Early detection and aggressive treatment are key to preventing a full-blown infestation. Ignoring mustard algae can lead to persistent problems and increased chemical costs.
Identifying Mustard Algae
Recognizing mustard algae early is crucial for effective treatment. Here’s what to look for:
- Appearance: It typically presents as a yellowish-brown or mustard-colored powdery substance.
- Location: It often appears on the shady sides of the pool, walls, steps, and even in pool equipment.
- Texture: It can feel slimy or gritty when touched.
- Resistance: Unlike regular algae, it brushes off easily but quickly returns if not treated properly.
The Treatment Process: A Step-by-Step Guide
Eradicating mustard algae requires a multi-pronged approach. Follow these steps carefully:
Test and Balance Water Chemistry: Ensure your pool water is properly balanced. Ideal ranges are:
- pH: 7.2 – 7.8
- Alkalinity: 80 – 120 ppm
- Calcium Hardness: 200 – 400 ppm
Brush Thoroughly: Vigorously brush all pool surfaces, including walls, floor, steps, and ladders. Pay close attention to areas where mustard algae is visible. Brush behind and around all pool fixtures.
Vacuum to Waste: Vacuum the entire pool to waste, bypassing the filter to prevent re-circulation of the algae spores.
Clean the Filter: Thoroughly clean your filter.
- Sand Filters: Backwash extensively.
- Cartridge Filters: Remove the cartridge and clean it with a filter cleaner solution or replace it.
- DE Filters: Backwash and recharge with fresh DE.
Shock the Pool: This is the most crucial step. Shock the pool with a triple or quadruple dose of chlorine shock (3-4 lbs per 10,000 gallons). Maintain this high chlorine level for at least 24 hours.
Add Algaecide: After shocking, add an algaecide specifically formulated for mustard algae. Follow the manufacturer’s instructions carefully. Quaternary ammonium compounds (“quats”) or copper-based algaecides are generally effective.
Run the Filter: Run your pool filter continuously for at least 24-48 hours to circulate the chemicals and filter out debris.
Re-Test and Adjust: After 24-48 hours, re-test your water chemistry and adjust as needed. Your chlorine levels should return to normal before swimming.
Repeat if Necessary: If the mustard algae persists, repeat the entire process.
Essential Pool Equipment Cleaning
Mustard algae can hide in pool equipment. Properly clean these items:
- Pool Toys and Floats: Soak them in a diluted chlorine solution (approximately 1 cup of chlorine per 5 gallons of water) for at least 30 minutes.
- Automatic Pool Cleaner: Thoroughly clean the cleaner, including the filter bag or cartridge. Run it in the shocked pool after algaecide is added.
- Skimmer Baskets: Clean and sanitize skimmer baskets.
Common Mistakes to Avoid
Many pool owners inadvertently make mistakes that hinder mustard algae treatment. Here are some common pitfalls:
- Insufficient Shocking: Not using enough chlorine shock is a common mistake. Mustard algae is resistant to normal chlorine levels.
- Poor Brushing: Inadequate brushing leaves algae clinging to surfaces, allowing it to re-establish.
- Ignoring Filter Cleaning: A dirty filter can re-circulate algae spores back into the pool.
- Skipping Algaecide: Algaecides provide an extra layer of protection and help prevent recurrence.
- Neglecting Pool Equipment: Failing to clean pool equipment allows algae to re-enter the pool.
Prevention is Key
Preventing mustard algae is always better than treating it. Regular maintenance is essential:
- Maintain Proper Water Chemistry: Regularly test and balance your pool water.
- Brush Regularly: Brush your pool surfaces at least once a week.
- Run the Filter Regularly: Operate your pool filter for at least 8-12 hours per day.
- Shock Periodically: Shock your pool every 1-2 weeks, especially during hot weather or after heavy rain.
- Use a Preventative Algaecide: Consider using a maintenance algaecide regularly, according to the manufacturer’s instructions.
Frequently Asked Questions (FAQs)
Why is mustard algae so hard to get rid of?
Mustard algae’s unique composition makes it resistant to normal chlorine levels. It also tends to cling to surfaces, making it difficult to eradicate completely without thorough brushing and aggressive shocking. Furthermore, its ability to survive outside of the pool in damp areas allows it to easily re-contaminate the pool.
Can I swim in a pool with mustard algae?
While mustard algae itself is not typically harmful, the high chlorine levels required to treat it can be irritating to the skin and eyes. It’s best to avoid swimming until the algae is completely eradicated and chlorine levels have returned to normal. The presence of algae also indicates that water sanitation is failing which might allow other harmful bacteria and pathogens to grow.
How do I know if my algaecide is working?
You should notice a gradual reduction in the mustard algae over a few days after applying the algaecide. The water may also appear clearer. However, it’s crucial to continue the entire treatment process, including shocking and filtering, even if you see initial improvement. Don’t rely solely on the algaecide – the shock treatment is crucial for complete eradication.
What type of shock should I use for mustard algae?
Calcium hypochlorite (cal-hypo) shock is a strong and effective option for treating mustard algae. It delivers a high dose of chlorine quickly. However, it can also increase calcium hardness levels, so monitor accordingly. Liquid chlorine (sodium hypochlorite) is also effective and doesn’t affect calcium levels, but may require more to achieve the same results.
How often should I clean my pool filter?
The frequency of filter cleaning depends on the type of filter and the pool’s usage. As a general rule:
- Sand Filters: Backwash when the pressure gauge reads 8-10 psi above normal.
- Cartridge Filters: Clean every 2-4 weeks or when the pressure gauge reads 8-10 psi above normal.
- DE Filters: Backwash when the pressure gauge reads 8-10 psi above normal. Disassemble and clean grids every 6 months to a year.
Always clean your filter after treating algae, especially mustard algae, to prevent re-circulation.
Can mustard algae grow in saltwater pools?
Yes, mustard algae can absolutely grow in saltwater pools. Saltwater pools still rely on chlorine generated by the salt cell to sanitize the water. If the chlorine levels are not maintained properly, mustard algae can thrive. Follow the same treatment process for saltwater pools as you would for traditional chlorine pools, ensuring adequate chlorine levels and proper salt cell function.
My mustard algae keeps coming back. What am I doing wrong?
Recurrent mustard algae often indicates incomplete treatment or a source of re-contamination. Ensure you are:
- Thoroughly brushing all surfaces, including behind ladders and in corners.
- Using a sufficiently high dose of shock.
- Cleaning your filter thoroughly.
- Sanitizing pool equipment and toys.
- Maintaining proper water chemistry on an ongoing basis.
Consider having your water tested professionally to identify any underlying imbalances.
What is the best algaecide for mustard algae?
Quaternary ammonium (“quat”)-based algaecides and copper-based algaecides are generally effective against mustard algae. Follow the manufacturer’s instructions carefully when using any algaecide. Some algaecides can stain pool surfaces, so test in an inconspicuous area first. Consider using a polymeric algaecide as a preventative measure after successful treatment.
Can I use baking soda to kill mustard algae?
Baking soda (sodium bicarbonate) is used to increase alkalinity, not to kill algae. While maintaining proper alkalinity is important for overall water balance, it won’t eliminate mustard algae. You need chlorine shock and algaecide for effective treatment.
How long does it take to get rid of mustard algae?
With diligent treatment, you can typically eliminate mustard algae within 3-7 days. However, stubborn cases may require repeated treatments. Consistent monitoring and maintenance are essential to prevent recurrence.
Is mustard algae harmful to my pool equipment?
While mustard algae itself isn’t directly harmful to pool equipment, the conditions that allow it to thrive (e.g., poor water balance, inadequate sanitation) can contribute to corrosion and other equipment problems. Maintaining proper water chemistry is crucial for protecting your pool equipment.
Can I prevent mustard algae with a UV system?
UV systems are primarily designed to kill bacteria and viruses, and can also help reduce algae growth. While a UV system can be a helpful addition to your pool sanitization system, it may not completely prevent mustard algae, especially in shady areas or if water chemistry is not properly maintained. It is best used in conjunction with traditional chlorination and algaecide for complete protection.