Controlling pool alkalinity involves adjusting its level up or down to maintain water balance, primarily by adding specific chemicals.
Maintaining the correct total alkalinity (TA) in your swimming pool is crucial for water balance, affecting pH stability and preventing potential damage to your pool's surface and equipment. Ideal total alkalinity levels typically fall between 80 and 120 parts per million (ppm).
Here's how to control alkalinity:
Testing Your Pool's Alkalinity
Before making any adjustments, you must test your pool's water to determine the current total alkalinity level.
- Use a reliable pool testing kit (such as test strips, liquid test kits, or digital testers) specifically designed to measure total alkalinity.
- Follow the kit's instructions carefully to get an accurate reading.
- Compare your test results to the recommended target range (80–120 ppm).
Lowering High Alkalinity
If your pool's total alkalinity is too high (above 120 ppm), you need to lower it. The most common method involves adding an acid to the water.
- Using Muriatic Acid: As noted in the reference, if your pool's alkalinity level is too high, you can lower it by adding muriatic acid to the water. A general guideline is to add 1 gallon of muriatic acid for every 10,000 gallons of water in your pool.
- Important Safety Note: Always handle muriatic acid with extreme caution. Wear protective gear (gloves, eye protection, long sleeves) and add acid to water, never water to acid. Dilute acid in a bucket of pool water before adding it to the pool, pouring it slowly into the deep end or in front of a return jet with the pump running. Avoid splashing.
- Using Dry Acid (Sodium Bisulfate): This is a safer alternative to muriatic acid, though it may require larger quantities. Follow the product's instructions for dosage and application.
- Add the acid in small increments, circulate the water for several hours, and retest the alkalinity before adding more. Lowering alkalinity often also lowers pH, which may need subsequent adjustment.
Raising Low Alkalinity
If your pool's total alkalinity is too low (below 80 ppm), you need to raise it.
- Using Sodium Bicarbonate (Baking Soda): This is the standard chemical used to increase total alkalinity in pools.
- Calculate the amount needed based on your pool's volume and how much you need to raise the alkalinity. Many pool supply stores or online resources offer alkalinity increase charts or calculators. A common estimate is about 1.5 lbs of sodium bicarbonate per 10,000 gallons of water to raise alkalinity by 10 ppm, but always verify with a calculator or chart.
- Add the sodium bicarbonate directly to the pool water, broadcasting it over the surface or adding it to a skimmer with the pump running.
- Allow the water to circulate for at least 4–6 hours, then retest. Add more if necessary until the target range is reached.
Summary Table: Alkalinity Adjustments
| Issue | Recommended Action | Chemical Used | Notes |
|---|---|---|---|
| High Alkalinity | Add Acid | Muriatic Acid or Dry Acid (Sodium Bisulfate) | Add slowly, dilute, wear PPE. May also lower pH. |
| Low Alkalinity | Add Alkalinity Increaser | Sodium Bicarbonate (Baking Soda) | Broadcast or add to skimmer with pump running. May also raise pH slightly. |
Regular testing and gradual adjustments are key to effectively controlling your pool's alkalinity and maintaining balanced water. For more detailed guidance on pool chemistry, consult a reputable pool care guide. (Note: This is a placeholder link)
