Keeping It Balanced

Discover your options in pool and spa water care. 


By Rachel Harper

Water Care Cipriano infinity pool night beautiful OverflowTo get the most enjoyment out of your pool or spa, you must keep the water clear and balanced. Sanitizers and testing kits/monitoring systems are both necessary for maintaining healthy water. There are many different types of each so it’s best to explore all of your options, then select the best water care system to fit your needs.

Chlorine

Chlorine is both a sanitizer that kills algae and bacteria, and an oxidizer that removes unwanted organic matter, such as oil and sweat. It is the most popular and affordable sanitizer used in pools, where its levels should be kept at 1 – 4 ppm. (Though not commonly used in hot tubs, the ideal chlorine level in hot tubs is 3 – 5 ppm.) When used in large doses of 10 ppm, chlorine functions as a shock; shocking or superchlorinating is necessary when the stabilizer level drops considerably or if algae begin to appear. 

To prevent chlorine from burning off in sunlight, cyanuric acid (a stabilizer) must be added to the water. Stabilized chlorine already contains cyanuric acid. It comes in granular forms, as well as sticks or tablets used for floating chemical feeders or filter baskets. When using unstabilized chlorine, cyanuric acid must be added separately and should be kept at 25 – 50 ppm in pools.

Saltwater Chlorinators 

Saltwater chlorinators are another option; they still use chlorine—just in a different form. Instead of adding chlorine tablets or granules, you will add several 50-pound bags of salt a few times a year. The water is sanitized via a saltwater chlorinator (chlorine generator) that produces chlorine as salt passes over the electrolytic cell. Since salt is a natural conditioner, saltwater pools leave your skin feeling smoother and do not irritate swimmers’ eyes. The green or eco-friendly aspect of saltwater pools is that you don’t have to handle or store the chlorine; it is produced automatically by the generator.

Because the chlorine produced in saltwater pools is unstabilized, you must add cyanuric acid to maintain a chlorine residual (unless the pool is indoors where it won’t be affected by sunlight). While you still need to check sanitizer, total alkalinity, and pH levels about once a week, the ideal chlorine level of 1 – 4 ppm is easier to maintain in saltwater pools. There is less fluctuation because chlorine is produced constantly when the pump is on. Saltwater chlorinators also include a digital control panel so you can monitor the salt level, which should be kept at 3,000 – 4,000 ppm. 

Non-chlorine Sanitizers

Chlorine is considered a primary sanitizer because it effectively sanitizes pool and spa water on its own. Bromine and biguanide work as chlorine alternatives because they are also primary chemical sanitizers. 

Bromine is the most common sanitizer for hot tubs and spas because it is suitable for warm, turbulent water. Bromine does not produce the same odor often associated with chlorine pools, and it works over a wider pH range. Additionally, bromine does not irritate the skin or eyes. Though it burns off more quickly in sunlight than chlorine, this is not a concern for hot tubs (which are covered on a regular basis) or indoor pools. Bromine levels should be kept at 4 – 6 ppm in both pools and hot tubs.


A second chlorine alternative is biguanide, which gives water a soft, silky feeling. It also prevents the fading of swimsuits. Biguanide cannot be combined with chlorine, bromine, or certain other products so biguanide-based systems are usually sold as a set (a sanitizer, shock, and clarifier) that must be used together. Recommended levels are 30 – 50 ppm for both pools and spas.


Other chlorine-free options include ozonators, ionizers, and mineral systems; however, these must be used in combination with a primary sanitizer. Ozonators (ozone generators) are widely used on hot tubs and come built-in on many models. They are far less common in pools, but systems are currently available from several companies. Ionizers use an electrolytic process to release algae-killing copper and silver ions into the pool or spa water. Mineral systems (mineral purifiers) use sticks or cartridges that slide into a pool’s or spa’s cartridge filter. As the water passes through the filter, it becomes sanitized as it picks up the natural minerals. Mineral systems can leave skin feeling softer than water containing chlorine alone. 


Monitoring & Testing

The chemical levels in your pool must be monitored or tested on a regular basis. This can be done through a manual test kit, a digital kit, or an automated display system. 

Test strips are the most popular testing method among pool owners. Users dip or swirl one of the strips in the water, wait the advised number of seconds, then compare the colors on the strip to the color comparator on the bottle. This will tell you the levels of chlorine, bromine, pH, etc. 

Liquid test kits use chemical reagents (substances that react with dissolved chemicals and elements to change the water’s color) to determine the parameter levels. To use them, collect a water sample, add the instructed number of drops of the reagent, and then compare the color of the water with the comparator. 

Digital test strip readers provide numerical results without color comparisons. Simply dip the strip into the water and insert it into the reader to see the levels of chlorine, pH, and total alkalinity. Be sure to follow the manufacturer’s instructions. 

Electronic floating sensors analyze the chemistry of your water and display the results on an indoor display unit. When levels are out of balance, the unit advises proper amounts of chemicals to add. It also displays the water temperature. 

One app allows you to view chemistry results right on your iPhone. After dipping the test strip in the water, take a picture of it with your iPhone; the app will then display results and recommendations right on the screen, plus keep a history of water care testing. 


Photo courtesy of Cipriano Custom Swimming Pools & Landscaping; Photograph by Ed Pirone