Chemical Balancing 101


There’s a lot that goes into maintaining a beautiful pool, with chemical balancing being one of the most important aspects. Keeping a properly balanced pool ensures clean, clear, safe, and sanitary pool water for swimmers. Beyond sanitation and clarity, unbalanced water is a destructive force that damages pool surfaces, heaters, and pumps. Without getting into higher level concepts like the Langelier Saturation Index and Total Dissolved Solids,  a basic understanding of chemical balance should include testing and management of at least 5 components. These elements are total alkalinity, pH levels, chlorine/sanitation, calcium hardness, and cyanuric acid.

The first step to balancing any pool is to collect and test water samples. Tests can be performed using test strips or a testing kit. If you’re testing a commercial pool, the kit will need to be compliant with local health codes. If you don’t have a test kit, a sample can be brought to your local pool professionals, or you can arrange for a service call. After you have your results from the test, you’ll know what needs to be adjusted. Never handle pool chemicals in a commercial setting without proper training and always follow manufacturer instructions and precautions when dealing with  your own backyard pool.

Chlorine/Sanitation

Maintaining proper chlorine levels in your pool keeps the water clean, bacteria-free, and safe for swimming. If the pool is subject to health department oversight, the health code will dictate the ranges that comply. Chlorine’s job is to kill microorganisms and remove contaminants (including bacteria and algae) that may be present in the pool water.

Ideal Range: 1.0-3.0 ppm (This may vary depending on the type of usage and local health requirements)

To Increase: Add a form of chlorine through the appropriate chemical feeder (Chlorine comes in multiple forms including tablets, liquid and granular forms)

To Decrease: Add a chlorine neutralizer, or partially drain and refill the pool with fresh water. Chlorine is also depleted by bather loads and UV rays from the sun.

pH Levels

pH levels indicate the acidity or basic qualities of your pool’s water. They should be checked every time you test the chlorine to ensure your pool water remains safe and clear. Proper pH levels prevent your pool water from becoming cloudy. pH values also have an impact on the effectiveness of the chlorine. Chlorine is more effective at lower pH, and becomes less effective as pH rises. If applicable, the local health department dictates the allowable range for pH. The comfort of swimmers is reduced at the lower end of the ideal range. Therefore, while the chlorine may be most effective, swimmers may complain of stinging eyes and irritated noses at a 7.2 reading.  

Ideal Range: 7.2-7.8 (on a pH scale from 0-14)

To Increase: Add soda ash (sodium carbonate)

To Decrease: Add a muriatic acid

Total Alkalinity

Managing total alkalinity is a level of chemical balance beyond sanitation, but it’s important because it supports stable pool conditions. This is because it is a stabilizer for pH levels (another element that needs to be balanced). When total alkalinity is at the proper level, pH levels fluctuate less. Total alkalinity refers to the amount of alkaline material in your pool water.

Ideal Range: 80-120ppm (parts per million)

To Increase: Use sodium bicarbonate(baking soda)

To Decrease: Use sodium bisulfate

Calcium Hardness

Calcium hardness is another component of water balance that promotes sparkling water.  If calcium hardness is too high the water can appear cloudy and leave scaly deposits on the pool surfaces and equipment. Scaling can damage equipment and create a rough condition on the pool shell. On the other hand, if calcium hardness is too low, the pool water becomes corrosive eating away at pool paint or plaster finishes. Calcium poor water damages pool heating elements and corrodes any metal fixtures exposed to the unbalanced water.

Ideal Range:200 -400 ppm

To Increase: Use calcium chloride

To Decrease: Partially drain your pool and refill it with fresh water, or use a flocculant to collect and vacuum excess calcium

Cyanuric Acid

Cyanuric acid is a chemical that helps protect chlorine from being destroyed by the sun’s violet rays. Essentially, it’s a sunblock for chlorine! Maintaining a proper amount of cyanuric acid helps retain chlorine levels for a longer period of time.

Ideal Range: 30-50 ppm

To Increase: Add a cyanuric acid water stabilizer to your pool water

To Decrease: Partially drain your pool and refill it with fresh water

Because the chemistry behind pool testing is so specific, it’s best to let a pool professional handle the job. A crystal clear pool needs to be maintained and balanced to remain beautiful safe and in compliance with your local health authority. If you are in need of professionals to check and balance your facility’s pool, our pool maintenance team has got you covered! Contact us today for help with any swimming pool chemistry challenges you may have this season!