1. Test and adjust Total Alkalinity
Total alkalinity is important to test and maintain. However, total alkalinity is largely similar and even correlated to cyanuric acid. Therefore, it is not as volatile as free chlorine or pH levels and does not require as frequent testing. A reliable rule of thumb is to test total alkalinity every other time you test pH levels. This should work out to about once per week.
Test strips are the easiest way to test total alkalinity. To conduct a test, follow the directions provided with the test strips. Typically, you will submerge one test strip in your pool water for several seconds. Then, you will hold the test strip at rest while the reagents on the strip react with the pool water. Finally, you will compare the color of the total alkalinity test with the color scale provided on the test strips container. It is unusual for your test color to exactly match one of the benchmark colors on the color scale. Use your best judgement to determine the exact value of your total alkalinity test result.
Test kits are another way to test total alkalinity. Test kits are very similar to test strips, except they require you to collect a small sample of pool water in a test tube and apply several drops of reagent to the water. After the reagent fully reacts with the water, you compare the color of the test water with a color scale provided in the test kit.
Test kits are more accurate than test strips. The level of accuracy may be important for free chlorine and pH tests. However, the accuracy test strips provide should be sufficient for total alkalinity tests.
How to Raise Pool Alkalinity
It should come as no surprise that the way to increase total alkalinity is to add alkaline materials to your pool water. There are three chemicals you may add that will increase total alkalinity. Which chemical you choose to add depends on your cyanuric acid and pH levels. If your cyanuric acid levels are also low, it is best to add stabilizer. This will both increase your total alkalinity and increase your cyanuric acid. If your pH levels are low, it is best to add soda ash. This will raise both pH and total alkalinity. If your pH and cyanuric acid levels are within recommended ranges, it is best to add baking soda to raise total alkalinity. Baking soda is the best way to raise total alkalinity with minimal effect to pH and cyanuric acid.
How to Lower Pool Alkalinity
High alkalinity means your pool water is buffering too much and possibly diluting the effectiveness of chlorine to the point it is unable to sanitize some contaminants in your pool or hot tub. Lowering total alkalinity is a two-step process. The first step is to lower pH by adding muriatic acid. Lowering pH will make your pool water more acidic and neutralize the alkaline materials in your pool. You should aim to lower your pH to a range of 7.0 to 7.2. The second step is to aerate your pool or hot tub to break up the remaining alkaline materials. This can be done by running your pool to increase circulation or running your hot tub jets. Water features or makeshift fountains can also be used for aeration.
Once total alkalinity is brought back down to your desired range, you will need to increase pH back to the recommended range of 7.4 to 7.6. Decreasing pH to 7.0 to 7.2 will have increased the efficacy of free chlorine. So, you likely won’t need to add stabilizer to increase cyanuric acid. Soda ash can be used to increase your pool pH level, but it also increases total alkalinity. Unless you overcorrected and lowered total alkalinity too much, you probably don’t want to increase alkalinity. Borax will increase your pool pH level without effecting total alkalinity. Therefore, borax is probably your best bet for increasing pH in this situation.
- Adjust Total Alkalinity
- Ideal range: 80 – 120 ppm
2. Test and adjust pH
The pH level of your pool should be kept between 7.2 and 7.8, with 7.4 as the optimal level to create a comfortable and safe experience for swimmers. The lower the pH level on this scale means you’ll need to add less chlorine to your pool water. As the pH rises in your pool, it causes the chlorine to become less active. For example, if your pH level is reading at an 8.0 level, your chlorine is about 10 percent active or effective.
- Adjust pH
- Ideal range: 7.4 – 7.6
3. Measure and adjust Calcium Hardness
It’s recommended that you test your pool water’s calcium hardness at least once a month, but it’s important to keep your eyes peeled for any signs of trouble as well. It can be difficult to recognize some subtle signs of calcium damage or to keep track of your test strip schedule/trips to the pool store, so a product like pHin is ideal. With pHin, you’re alerted every time you need to complete a test strip; it will read your results for you and make recommendations accordingly, and help maintain your pH and total alkalinity levels as well, which we now know are vital to maintaining healthy calcium hardness.
- Balance Calcium Hardness
- Ideal range: 200 – 400 ppm
How to increase calcium hardness:
To increase your pool water’s calcium hardness use calcium chloride. Follow the usage instructions printed on the packaging.
How to decrease calcium hardness
- Partially drain your pool and refill it with fresh water.
- Use a flocculant to collect and vacuum excess calcium.
4. Add sanitizer (chlorine) to your water
Sanitizers are used to kill bacteria and inhibit the growth of viruses, algae and other organic contaminants that enter your pool water by way of wind, rain, dust and swimmers. The most common pool water sanitizer is chlorine. Chlorine is the most cost effective way of sanitizing your pool and has been a product of choice for over 100 years. Nothing purifies and disinfects better than chlorine. Chlorine must be in your pool at all times and maintained at the ideal “free available chlorine” range. Free available chlorine is the amount of chlorine left to kill new bacteria entering the pool. This is what sanitizes your pool continuously.
- Add sanitizer (chlorine, bromine, or biguanide)
- Ideal range: 3 ppm (chlorine)
Chlorine comes in a few forms:
- Chlorine tablets
- Granular chlorine (pool shock)
- Liquid chlorine
- Salt chlorine generator
5. Check and adjust Cyanuric Acid
Cyanuric acid is often sold as a conditioner or stabilizer because it prevents chlorine in the pool from weakening in the sunlight. Use test kits or strips designed to measure cyanuric acid, so you can determine how much acid to add to your pool. To significantly raise levels, dissolve powdered cyanuric acid or add a liquid version. You can also add stabilized chlorine for regular maintenance.
The ideal level for cyanuric acid is between 30 and 50 ppm.
6. Measure your water’s Total Dissolved Solids
There’s a special number to measure it:
- Measure Total Dissolved Solids
- Ideal range: Less than 2,000 ppm
This number represents how many of those substances have dissolved in your water.
It’s regular for your pool to have a TDS level of a few hundred or so, even 1,000.
But there does come a point when a pool’s TDS level is too high, and the only effective solution is draining and replacing water.
If your pool’s TDS level is below 2,000 ppm, then no adjustments are needed.
However, if TDS levels rise above 2,000 ppm, then begin draining the pool in small increments. With each drain, replace with fresh water. Keep testing until TDS levels are under 2,000 ppm.
7. Shock your swimming pool
Your pool should not need to be shocked on any regular basis to keep the water clear and clean, especially if you have an ozone system. Sometimes you will need to use chlorine-based shock to eliminate the nitrates from bird, animal, or human defecation that turn into food for algae. If you need to use shock (if you don’t have an ozone system), use it at night when no one is in the pool and the sun doesn’t have time to degrade the chlorine-based shock’s effectiveness. Or, use non-chlorine shock if you plan on swimming any time soon, or during the day since it’s chlorine-free and its effectiveness won’t be weakened in the sun.
