Swimming pools require a careful balance of water chemistry to stay clean, safe, and comfortable. One of the most overlooked but critical aspects of pool maintenance is alkalinity. When there is no alkalinity in the pool, several problems can arise, from damage to pool surfaces and equipment to irritation of swimmers’ skin and eyes. Alkalinity serves as a buffer for pH, and its absence can lead to significant fluctuations that make water conditions unstable. Understanding what causes low or no alkalinity and knowing how to correct it is essential for any pool owner or maintenance professional.
Understanding Total Alkalinity
What Is Alkalinity?
Total alkalinity refers to the concentration of alkaline substances in your pool water, primarily bicarbonates. It helps to stabilize the pH level, preventing sudden shifts that can cause damage or discomfort. Ideally, the total alkalinity in a pool should be between 80 to 120 parts per million (ppm). This range supports balanced water chemistry and helps maintain a consistent and safe pH level.
Why Alkalinity Matters
Without the proper level of alkalinity, pH can fluctuate rapidly. This condition, often called ‘pH bounce,’ makes it difficult to keep pool water balanced. Even if the pH is correctly adjusted, without a stable alkalinity level, the water will not maintain its balance for long. This leads to potential damage to the pool’s structure and discomfort for swimmers.
Consequences of No Alkalinity in Pool
Corrosion and Equipment Damage
Low or no alkalinity makes pool water corrosive. This aggressive water can wear down metal components such as ladders, railings, pump parts, and filters. Over time, these parts may rust, deteriorate, or fail entirely, leading to costly repairs or replacements.
Plaster and Surface Damage
In pools with plaster or concrete finishes, a lack of alkalinity can lead to surface etching or staining. The acidic nature of low-alkalinity water draws calcium from the plaster, weakening it and leaving rough, discolored patches. This type of erosion not only looks bad but can shorten the life of the pool surface.
Uncomfortable Swimming Conditions
Swimmers often complain of itchy skin, burning eyes, or dry hair when swimming in a pool with no alkalinity. These symptoms occur because unstable pH caused by low alkalinity irritates the skin and mucous membranes. Maintaining proper alkalinity helps keep swimmers comfortable and reduces the need for chemical adjustments after every swim.
Difficulty Balancing Chemicals
When alkalinity is missing, maintaining a stable pH becomes an ongoing challenge. This instability leads to frequent chemical use, especially acids or bases, to try to correct the water. This back-and-forth adjustment wastes time, chemicals, and money.
Causes of Low or No Alkalinity in Pool
Heavy Rainfall
Rainwater is naturally acidic and lacks buffering compounds. After heavy rains, the dilution and acid content can significantly lower alkalinity in your pool. This is especially true in areas with acidic rainfall or during storm seasons.
Overuse of Acidic Chemicals
Adding too much muriatic acid or sodium bisulfate to adjust pH can unintentionally drop alkalinity. Pool owners trying to fix high pH often reduce alkalinity as a side effect, sometimes eliminating it entirely if corrections aren’t carefully made.
Frequent Water Replacements
Draining and refilling parts of the pool with low-alkaline tap water can gradually decrease total alkalinity. Depending on your water source, this process can eventually lead to zero alkalinity if no adjustments are made.
How to Fix No Alkalinity in Pool
Step-by-Step Recovery Process
- Test the Water: Always begin by using a reliable test kit to confirm that alkalinity is at or near zero.
- Add Alkalinity Increaser: Use sodium bicarbonate (baking soda) to raise the total alkalinity. Follow manufacturer guidelines for dosing. Typically, adding 1.5 pounds of sodium bicarbonate per 10,000 gallons of water raises alkalinity by about 10 ppm.
- Distribute Evenly: Broadcast the product across the pool surface with the pump running to help dissolve and circulate it.
- Retest After 612 Hours: After the chemical has had time to work, retest alkalinity levels and make further adjustments if necessary.
- Monitor pH: After raising alkalinity, you may see a small rise in pH. Adjust pH back to the ideal range of 7.27.6 if it gets too high.
Preventing Future Drops
Once alkalinity has been restored, maintaining it becomes easier. Test the water at least once a week. If you live in an area prone to rain or use acid often, consider adding a buffer proactively to prevent alkalinity from dropping again. Installing a pool cover can also help limit dilution from rain and debris.
Additional Tips for Pool Owners
Know Your Pool Volume
Accurate chemical adjustments depend on knowing the volume of your pool. Without this information, you might under- or overdose, leading to further imbalance. Measure your pool carefully and use that data whenever applying treatments.
Use a Logbook
Keeping a record of chemical additions, water test results, and weather events can help you spot trends. If you notice that alkalinity drops every time it rains, you’ll be better prepared to act preemptively in the future.
Balance Alkalinity First
When treating water chemistry, always adjust total alkalinity before pH. Since alkalinity affects how pH behaves, stabilizing it first allows other adjustments to hold more effectively. This order simplifies water treatment and leads to longer-lasting balance.
When to Seek Professional Help
If you repeatedly find your pool has no alkalinity despite adjustments, it may be time to call in a pool professional. Persistent problems could indicate a larger issue, such as malfunctioning equipment, faulty test kits, or water source imbalances. A professional can conduct a full water analysis and provide expert advice on long-term solutions.
Having no alkalinity in a pool is a serious issue that can lead to a range of costly and uncomfortable problems. From damaging surfaces and equipment to making swimming unpleasant, low alkalinity affects nearly every aspect of pool health. By understanding the causes, recognizing the symptoms, and applying correct treatments, pool owners can restore and maintain proper alkalinity levels. Regular testing, preventive care, and consistent chemical management are key to keeping your swimming pool clean, safe, and enjoyable all year long.