People often confuse mustard or yellow colored spots in the pool as dirt, but they are not dirt. They are unpleasant and stubborn algae that develop on the pool's floor or walls. If left untreated, mustard algae can cause severe damage to the pool and its equipment and affect the water quality of the pool.
In this blog, you will read about everything, from the meaning, causes, and prevention of mustard algae to the treatment method.
What is Mustard Algae?
Mustard or yellow algae is a rigid form of green algae that is resistant to chlorine and many other common sanitizers. The green algae tends to float freely on top of the water, and mustard algae sticks firmly to the pool's floor or walls. It also sticks to the other pool objects like lights, ladders, toys, and filters.
Mustard algae is often mistaken for dirt or sand, as it is found at the bottom or sides of the pool. The algae becomes challenging to treat as it is persistent in nature. It is often considered tough to remove them from the pool as they resist chlorine and standard cleaners.
Causes of Mustard Algae in the Pool
Mustard algae develop in the pool due to the following reasons:
- Chemical Imbalance: The imbalance of pH or alkalinity levels can promote mustard algae growth.
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External Contaminants: The Presence of unwanted substances like debris, phosphates, or pollen contaminates the water, which further causes algae growth.
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Poor Maintenance: Irregular and improper cleaning favors algae development.
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Circulation and Filtration: Inefficient pool circulation and setup of weak filtration systems allow yellow algae growth.
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Climatic Factors: Warmer climates with atmospheric and environmental changes often increase the risk of algae.
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Use of Pool: How frequently and carefully you use the pool affects the algae development.
How to Detect Mustard Algae?
It is highly suggested to detect the early signs of mustard algae and get rid of them. If you find strange yellow colored patches, here's a list of things you should do to detect whether it's algae or something else:
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Check for Yellow Patches: If you see dusty, yellow, or brown spots, it is possible they are mustard algae and not the regular dirt, sand, or stains.
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Use a Pool Brush for Testing: Arrange an antimicrobial pool brush and use it for gently scrubbing the area that has yellowish patches. This technique will easily give you a clue about the nature of the substance.
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Observe the Reaction After Test: After brushing, you will see one of the three reactions: either it will stay fixed, shift slightly, or disperse into a cloudy haze. If the spot doesn't move, it is likely a metal stain, which requires different treatment. If it shifts, it could be sand or dirt.
| Notes | If the spot disperses into a cloud, then that's a sign of mustard algae, as it spreads quickly and clouds the water when brushed. |
How to Treat the Mustard Algae in the Pool and Its Filter?
Check and Clean Your Filter
The first step of treating the mustard algae is to check and clean the filter thoroughly. This step will help in discovering algae spores clearly. You can run the pump for 24 hours a day during the whole cleaning process to have the best results.
Balance the Chemical Level in Water
After cleaning the filter, adjust the pool's chemistry. During this process, make sure the pH is 7.8 or slightly higher, total alkalinity is between 80-120 ppm (parts per million), cyanuric acid (stabilizer) is between 25-75 ppm, and FAC (Free available chlorine) is between 2.0 - 2.5 ppm.
Break the Algae Grip by Brushing
Use a pool brush and aggressively scrub the walls, steps, ladders, and area with the presence of mustard algae. This step will lose the grip of algae on surfaces and make it easy for chemicals to enter and kill them. Use a wire-bristle brush for plaster or concrete pool surface and a nylon brush for vinyl and fiberglass pool surface.
Shock the Pool
Use a high dose of chlorine shock three times at every 12 hours of intervals, as algae are highly chlorine resistant, and it won't fade away with one shock. After every interval, make sure to circulate or mix the water so that the effect of shock reaches every corner of the pool.
Again, Clean the Filter
Once you are done with the final shock treatment, turn off the pump and clean the filter for one more time. This step will help in removing stuck algae spores and other debris from the system.
Add Clarifier
Check the FAC level; if it is below 5 ppm, add a water clarifier. This will help in cleaning the water and removing the dead mustard algae from the pool. After adding a clarifier, vacuum the pool thoroughly with the waste setting to remove other contaminants.
Final Check
In the last step, retest the chemical balance and cleanliness of the water and pool. Once done, make sure the phosphate level is below 100 ppb (parts per billion) as it is a food source for algae.
How to Prevent Mustard Algae?
Prevention is better than a cure. Therefore, stopping the growth of mustard algae is much easier than treating the situation once it gets worse. The algae can quickly spread if ignored and not cared for properly.
By following the steps below regularly, you can keep your pool free of mustard algae for the long term.
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Maintain a Balanced Chemical Situation in the Pool
It is important to check the chemical balance of the pool regularly. The pH, alkalinity, and chlorine level should be within the ideal range. Make sure to maintain a free available chlorine level at around 4 ppm for safety.
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Keep Your Pool Neat and Clean
Brushing and vacuuming the pool once a week also helps in preventing algae growth. It is good to focus on areas like corners, steps, ladders, and behind pool lights while cleaning.
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Sanitize Pool Equipment and Toys
Dirty equipment and toys can carry algae into the water from outside sources. To prevent this, always clean and disinfect them, preferably using a disinfectant spray.
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Promote Good Hygiene
Swimmers are advised to clean their swimsuits and always shower before entering the pool. This helps in avoiding the entrance of algae or other contaminants.
Keep Your Pool Algae-Free!
It can be challenging to get rid of mustard algae. However, with proper knowledge, tools, and methods, it can be eliminated.
Ultimately, prevention is the only key. Hence, make sure to follow the preventive measures carefully to keep your pool fresh and ready to use.
