Maintaining Water Balance in Your Pool: Understanding pH, Alkalinity, and Chlorine

Keeping Your Pool Safe and Healthy

If you are new to pool ownership, you may not be aware of all that goes into creating a safe and healthy environment for swimming. It’s not as simple as just putting in chlorine. It is important for all of your chemicals to be balanced because if one chemical is slightly off, it can throw off all the other chemicals and lead to bacteria in your pool. Fortunately, it is not difficult to balance your pool water chemicals, and once you get the hang of it, it will become routine. Let’s take a look at the different types of chemicals, and why it’s so important to keep them in balance.

Why is Balanced Pool Water Important?

Keeping your pool water balance prevents damage to the pool and provides a safe, healthy, and comfortable environment for swimming. If your chlorine is too high, your skin and eyes may become irritated, and you could get sick. On the other hand, if it’s too low it won’t be very effective in terms of killing bacteria, algae, and other contaminants. When your pH is too high, it can cause cloudy water and scale deposits on the pool walls and equipment, while pH that’s too low can cause the pool surfaces and equipment to become etched and corroded.

Testing Your Pool Water

You can stay on top of the balance of your pool water by using a test kit once a week to test it. If you discover that something is off-balance, you will need to test daily until the problem is resolved. Here’s how to test and balance your pool water:

• Collect everything you’ll need. This includes a test kit, alkalinity balancer, pH balancer, water-hardness balancer, and stabilizer or conditioner.
• Calculate the volume of your pool water. You may already know this, but if you don’t, it’s pretty easy to calculate. All you need to do is multiply the length of the pool by the width and the depth, then by the multiplier. The multiplier depends on the shape of your pool: it’s 7.5 for a square pool and 5.9 for a round pool.
• Test the water. Your test kit should cover at least:
  • Cyanuric acid: this chemical keeps sunlight from burning away your pool’s chlorine. Ideally, it should be between 30 and 50 ppm, and if it’s low, you may need to add more.
  • pH: The pH refers to how acidic or basic your pool water is, and the ideal pH for a pool is just slightly basic, at 7.4 to 7.6. Below 7.2, pool water will sting your eyes and damage your pool. Above 7.8, you could end up with cloudy water that irritates your skin and causes scale buildup on the sides of your pool. A pH increase like sodium carbonate can raise the pH, and if your total alkalinity is too low, adding baking soda can increase the alkalinity. If your pH is too high, add sodium bisulfate or muriatic acid.
  • Total alkalinity: Test your alkalinity first, because it will act as a pH stabilizer. It should be between 80 and 120 ppm, and if you need more, you’ll need to add an increaser, while to lower alkalinity you will need to add sodium bisulfate.
  • Calcium hardness: Calcium buildup can look like a white line of scale forming near the water line. This looks dirty, and it can also damage your pool material and equipment. Your pool’s calcium hardness should be between 200 and 400 ppm. Adding calcium chloride will increase your pool’s calcium hardness while decreasing calcium hardness requires partially draining the pool and refilling it with fresh water.
  • Free available chlorine: A safe range for free available chlorine is between 2.0 and 4.0. Chlorine acts as a disinfectant or sanitizer, killing off living organisms, bacteria, and other contaminants. Balancing it is the final step in balancing your pool’s water. Chlorine is available in liquid, granular, or tablet form, as well as in salt chlorine generators, but it’s not the only sanitizer you can use in your pool.
    • Bromine is similar to chlorine but has less odor and is gentler on hair and skin. However, it costs more than chlorine and is not stabilized, so it burns off quickly in sunlight.
    • Biguanide is also more expensive than chlorine because it must be used as part of a chemical sanitization trio. It cannot be used with algaecides, shocks, and other traditional pool chemicals.
    • Minerals are a less common way to sanitize a pool, but they can be used to supplement chlorine and salt generators.
• Balance your water. Make sure the pump is circulating, then add whichever chemicals you’ve determined are necessary through your testing. Follow instructions carefully before adding more chemicals than recommended, and understand that you may need to add chemicals in stages, waiting at least six hours between treatments.
• Measure the total dissolved solids in the water. Total dissolved solids (TDS) is the measurement of the substances that have dissolved in your water, whether that’s chemicals, salts, or contaminants. Up to 1,000 TDS is considered acceptable, and if the level rises above 2,000 you will need to drain a little bit of the pool water and refill with fresh water, testing and adjusting until the level is back down.
• Mind the pool’s temperature. At higher temperatures, you will probably need fewer chemicals, while at lower temperatures, balancing the water may require more chemicals. One exception is chlorine, which may be used faster when the temperature is warmer because that’s when bacteria and algae thrive.
• Shock the pool. To refresh your pool water and keep it sanitized, clean, and safe, you should shock it about once a week if people are swimming in it every day. To do this:
  • Using warm water, fill a five-gallon bucket.
  • Mix a one-pound bag of pool shock slowly into the bucket.
  • Stir, using a stick, until the shock has dissolved.
  • Gradually pour the bucket of shock water into the pool, walking around the pool to distribute it but pouring most of it into the deep end.
• Test again. About six hours after you’ve shocked your pool, bring the test kit back out to check the water. By double-checking all the levels, you can determine how well you’ve done at balancing your pool. Make any adjustments, correcting chemical imbalances as soon as possible.

Trust Aaron Pools and Spas to Help You Care for Your Pool

If you need help keeping your pool clean and clear year-round, reach out to the professionals at Aaron Pools and Spas. Established in 1972, this family-owned-and-operated business has a dedicated, award-winning team with over 400 years of combined experience. We love to help improve the quality time that families spend together at home, and that’s why we’ve installed more than 2,000 swimming pools and hot tubs, from Cape Cod to Connecticut. We also offer pool cleaning products to make sure your pool looks beautiful, feels amazing, and is safe. For the best possible service from our highly experienced installation team, call 508.996.3320 or contact us today.