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Pool Care Basics

How to sanitize, test, and balance your swimming pool water

By Kimberlee Courtney


Along with endless hours of fun with family and friends, owning a swimming pool also brings with it the need for regular upkeep. Maintaining a clean pool is essential to the health of swimmers and will preserve the beauty and function of the structure. Learn how to treat your so you and your family can enjoy swimming all season long.

Sanitize the Water

Proper water care is one of the most important parts of maintaining your pool. Over time, organic contaminants such as sweat, lotion, and other germs build up in the pool. Treating your pool with sanitizers destroys the organic matter and prevents the growth of bacteria and algae, keeping the water clean and safe to swim in.

Chlorine is the most widely used and highly effective sanitizer and oxidizer. It can be added to a pool in the form of granules (dichlor) or tablets and sticks (trichlor), which are used in floating chemical feeders or filter baskets. Chlorine also functions as a shock when used in large doses of 10 ppm; you may need to shock (superchlorinate) your pool when there is a major drop in stabilizer levels or if you see algae growth.

Some pool owners have been converting to saltwater sanitizing systems, which eliminate the need to add chlorine by hand. Instead, several pounds of salt (sodium chloride) are added to the pool, and as the water (and dissolved salt) passes through the system, a chlorine generator containing a catalytic cell converts the salt to chlorine. Once the water is sanitized, the chlorine reverts back to sodium chloride. Since most of the water contains saline, it becomes smooth to the touch.

There are also non-chlorine stabilizers like bromine and biguanide, which are gentler on the skin and eyes and make the water feel silky smooth. Bromine is generally used more in spas and hot tubs rather than pools because it is more stable in high temperatures and is effective at higher pH levels. Also, because it burns off easily in sunlight, it is better kept in hot tubs since they remain covered when not in use.

Biguanide is often sold as a set (a sanitizer, shock, and clarifier) because it cannot be combined with chlorine, bromine, or mineral sanitizers. Biguanide pools also must be oxidized with hydrogen peroxide because they are incompatible with monopersulfate and chlorine shock. Biguanide is more expensive than chlorine or bromine, but steadier in sunlight than bromine. Biguanide’s benefit over chlorine is that it will not dry or irritate skin or fade swimwear.

Supplemental sanitizers, including mineral systems, ionizers, and ozonators can be utilized to reduce the use of a chemical sanitizer. Mineral sanitizer systems (mineral purifiers) and mineral ionizers consist of sticks or cartridges that slide into a pool’s or spa’s cartridge filter and release metals (typically a combination of silver, copper, and zinc) into the water, which helps sanitize the water and control algae. Mineral systems can leave skin feeling softer than water containing chlorine alone.

Ozonators (ozone generators) release ozone, a short-acting oxidizer, into the water. They are commonly used on hot tubs and come built-in on many models. They are less common in pools, but some systems are available from several companies.

Balance the Water

Balanced pool water ensures the efficiency of your sanitizer and prevents scale from forming on the pool’s surface and equipment. Bacteria continuously enter the pool from many sources, so it’s important to monitor or check the chemical levels in your pool on a regular basis.

Most pool owners use test strips or liquid kits to examine their pool’s water chemistry. Test strips are dipped or swirled in the water for a few seconds and then removed. After waiting the advised number of seconds, users compare the colors on the test strip to the color comparator on the bottle to read the levels of chlorine, bromine, pH, etc. in the water.

Liquid test kits require users to put a sample of water into a plastic comparator and add drops of chemical reagents (substances that react with dissolved chemicals and elements to change the water’s color) to determine the parameter levels.

Newer testing methods have become available in the past few years including digital test strip readers, electronic floating sensors, and even an app. Digital test strip readers provide numerical results without color comparisons. Following the manufacturer’s instructions, users simply dip the strip into the water and then insert it into the reader to see the levels of chlorine, pH, and total alkalinity.

Electronic floating sensors evaluate the water’s chemical levels and display the results on an indoor monitor. The device also displays the water temperature and advises proper amounts of chemicals to add when the levels are out of balance.

Pool owners with an iPhone or Android phone can download an app and check the chemistry levels right on their phone. After dipping the corresponding test trip in the water, take a picture of it with your smartphone; the app will then display results and recommendations right on the screen. It also keeps a history of your chemistry results for easy reference.

Photo courtesy of Mission Valley Pools & Spas, Inc.




Water Care Companies and Experts

Learn more about these recommended manufacturers of pool water care products (sanitizers, test strips, test kits, chlorine, chemicals, etc.) from the company experts.


Joe Sweazy

Technical Sales and Services Manager 

HACH Company/ETS Business Unit, manufacturer of AquaChek®

Joe Sweazy has been with HACH Company for 15 years. He has published more than a dozen articles on pool and spa water chemistry and has presented numerous seminars at conferences of the Association for Pool and Spa Professionals (APSP) and at the World Aquatic Health Conference.

“We created AquaChek test strips to give pool and hot tub owners the fastest, easiest, and most accurate way to monitor the health of their water. Fast, reliable testing has made AquaChek the world’s #1 brand of pool and spa test strips. When testing is easy, owners test and treat their water more often, resulting in better managed pools and greater satisfaction and enjoyment. Additionally, AquaChek has introduced the TruTest Digital Test Strip Reader, which gives you results electronically in as little as 30 seconds. It takes the guesswork out of color matching for those who have trouble distinguishing colors.” 



Richard LaMotte

Vice President, Sales and Marketing

LaMotte Company

Richard LaMotte has been an active member of the pool and spa industry since 1984. In 1987 Mr. LaMotte co-developed the company’s successful WaterLink® labs and software, as well as authoring two pool chemistry handbooks. Mr. LaMotte obtained a Bachelor of Science in business administration/ marketing from St. Andrews College (N.C.).

“New apps for iPhones and Androids are being introduced every day. It was time to give one to consumers who wanted to take better care of their pools. When we discovered these devices could be used to scan a reacted pool test strip and analyze the results, it made sense to combine our treatment program to this new strip-scanning technology. Now a pool or spa owner can use an Insta-LINK® test strip, take a quick photo, and have results and recommendations in seconds using our Insta-LINK app. With a subscription, they can get detailed treatments, track history, and do problem solving. This app is ideal for the colorblind and for those who don’t know how much product to add based on test results. It’s the perfect combination of sophisticated technology with our simple testing platform—one we’ve been perfecting since the 1920s.”



Jim Tuegel

Merchandise Manager

In the Swim

Jim Tuegel is the merchandise manager for In The Swim. He has worked in the pool industry for over 15 years. Prior to joining the merchandising department in 2006, he was the supervisor of Parts and Technical Sales.

“In the Swim is America’s #1 direct source for pool supplies. We are a catalog and online retailer and offer a wide selection of quality swimming pool and hot tub/spa supplies, as well as accessories for inground and aboveground pools and the backyard. The one constant factor of In the Swim’s growth has been our unyielding commitment to maintaining the highest level of customer satisfaction through our dedication to quality products at the best possible prices.”