Pool Chemicals Decoded: The Essential Manual for Fresh Pool Water

man's hand holding a pool chemical test strip against a color chart

Summer is here, and you’re ready for a swim! As a new pool owner, there’s much to grasp about pool maintenance and ensuring your water meets high standards.

Water quality entails having your pool water thoroughly sanitized, free from pathogens that could pose health risks. Maintaining superior water quality is essential for safe swimming and a fun-filled season.

However, it’s not enough for your pool to just look clean. Keeping it germ-free requires regular water testing, understanding the results, and making the appropriate adjustments.

The Importance of Excellent Pool Water Quality

A pool, by itself, is merely a large amount of water. Under the warm summer sun, this water can become a haven for invisible intruders such as bacteria, protozoa, and algae. These microorganisms can result in illnesses, infections, and skin irritations. Additionally, some contaminants can damage the pool’s surface and equipment if neglected.

Achieving the safest swimming conditions involves chemically balanced and disinfected pool water. Ridding pool water of impurities helps in reducing harm to pool equipment. Upholding high water quality standards is a way to protect the substantial investment of your pool, ensuring its durability.

Assessing Safe Swimming Conditions in Your Pool

Sometimes, poor water quality is obvious, such as when the water looks cloudy or green. However, a pool can appear crystal clear yet still contain hazardous microorganisms beneath the surface. Water testing is crucial to verify it is devoid of pathogens and fit for swimming.

hands using a water test kit, applying drops of reagent

Various Methods to Test Your Pool Water

Numerous methods are available to assess pool water quality. Testing the water takes only a few moments, with results that are straightforward to interpret.

Test Strips – Pool test strips are small, chemically treated papers that you dip into your pool water. For testing, select a location away from the skimmer and return jets. Firmly hold the strip and submerge your arm elbow-deep into the water, or use a clean glass to gather a water sample. After approximately 15 seconds, match the strip’s sensor pads to the color code on the container. If any readings are off, take measures to balance the water.

Test Kit – Water test kits, while seeming more intricate than test strips, often yield more accurate results. Typically, these kits comprise a collecting tube with a built-in color chart and bottles of liquid reagents for each water quality parameter. Follow the kit’s instructions to assess your water and adjust the chemicals as needed.

Digital Tester – Several digital testers are accessible in the market. Though they might be costly, digital pool water testers generally provide high accuracy and ease of use, according to Pool Care for Dummies. They evaluate your water quality and display the results on a digital screen.

If conducting these tests feels daunting, a nearby pool supply store can test your water for you. Collect between 12 and 16 ounces of pool water in a clean, empty bottle, seal it, and take it to your pool store for analysis.

Five Fundamental Elements of Pool Water Quality

Five key parameters determine overall water quality: chlorine, pH, total alkalinity, calcium hardness, and stabilizer. Let’s delve into each one.

hand holding a chlorine tablet, with blue swimming pool water blurred in the background

Chlorine (or anothersanitizer)

What is Chlorine?

According to the Centers for Disease Control (CDC), chlorine is highly effective in destroying bacteria in pool water and stopping the spread of diseases. It also helps in eliminating dirt and preventing algae formation.

Other options for sanitizing pools include bromine and PHMB, also known as biguanide. Saltwater pools generate chlorine through a chemical process. The information below is specific to chlorine-based additives.

Ideal Chlorine Levels

To maximize disinfecting efficiency, chlorine levels in your pool should be maintained between 1 and 3 parts per million (1 ppm-3 ppm).

The Importance of Chlorine Balance

Maintaining the right chlorine levels ensures your pool remains clean and free from harmful microorganisms.

When to Measure Chlorine Levels

Check chlorine levels two to three times a week, with additional checks after rain or heavy pool usage.

How to Adjust Chlorine Levels

Chlorine comes in liquid, granular, or tablet forms. If unsure which form is best for your pool and routine, consult a pool service professional.

To increase low chlorine levels, add chlorine using your preferred method.

Excessive chlorine might be caused by overdosage or reduced sunlight exposure. Sunlight generally lowers high chlorine levels. Using a chlorine neutralizer is another option, though it will also affect the pool’s pH.

pH

What is pH?

pH measures the acidity or alkalinity of your pool water, and ranges from 0 to 14.

Why is pH Balance Important?

Chlorine is most effective when pH levels are balanced. Elevated pH levels reduce chlorine’s ability to kill germs. Though low pH doesn’t affect chlorine’s disinfecting power, it can increase chlorine levels, potentially causing skin and eye irritation and damaging pool equipment.

Optimal pH Levels

A pH of 7 is neutral, values under 7.0 are acidic, and those above 7.0 are alkaline. The ideal pH range for pool water is between 7.2 and 7.8, though some experts prefer a narrower range of 7.4 to 7.6.

When to Test pH Levels

Assess the pH levels in your pool at least once a week, more frequently if there’s heavy rain or high pool usage. Regular testing helps you detect and correct pH changes early.

How to Adjust pH Levels

If your pool water’s pH is too high or low, it can irritate the skin and eyes and reduce chlorine effectiveness. Unbalanced pH can also corrode pool equipment. As a pool manager, you must regularly test and adjust pH levels.

To correct pH, use a water balancer. A pH increaser like sodium carbonate will raise a low pH, while a pH decreaser like sodium bisulfate will lower a high pH. Follow product instructions carefully to avoid over-adjustment.

children's feet splashing by the side of a swimming pool

Alkalinity

What is Alkalinity?

Alkalinity works alongside pH to maintain stability, even when other chemicals are added that could alter pH.

Why is Balanced Alkalinity Important?

High alkalinity can elevate pH, lead to cloudy water, hinder circulation, and obstruct filters. Low alkalinity might cause skin and eye irritation and harm pool surfaces and equipment. Inadequate alkalinity doesn’t stabilize pH, leading to significant pH fluctuations.

Ideal Alkalinity Levels

Pool experts recommend keeping alkalinity between 80 and 120 ppm, though some professionals find a range of 100 ppm to 150 ppm acceptable.

When to Test Alkalinity Levels

Check alkalinity levels weekly to ensure pH stability.

How to Adjust Alkalinity

To decrease high alkalinity, use dry granular muriatic acid. Add in small amounts and retest after a few hours before entering the pool.

An alkalinity booster corrects low levels. Alternatively, to increase alkalinity without altering pH, add baking soda (bicarbonate of soda) with the pump and filter running, adding a pound at a time.

Calcium Hardness

What is Calcium Hardness?

Calcium hardness measures the amount of calcium carbonate in your pool water. When calcium is lacking, it needs to be supplemented.

Why Maintain Calcium Hardness?

As cited by Trouble Free Pool, “soft” water or water with low calcium can draw calcium from various surfaces like plaster, tile grout, stone, cement, and fiberglass. Low calcium can also corrode metal parts like handrails, pipes, and equipment, and cause foamy water in spas.

On the other hand, excessive calcium can cause surface staining, skin and eye irritation, cloudy water, and scaling on rails and within pipes and filters.

Balancing calcium hardness protects your pool’s surfaces and equipment.

Optimal Hardness Ranges

For plaster or concrete pools, the recommended hardness range is between 200 and 400 ppm. For fiberglass pools, an acceptable range is from 100 to 330 ppm.

How to Test Water Hardness

It is advised to measure water hardness levels monthly.

Balancing Calcium Hardness

After significant rainfall or intense heat, you may find calcium levels in your pool to be low; adjust this by adding calcium chloride or calcium chloride dihydrate.

Increased calcium levels can occur due to evaporation, leaks, or extensive use. Pool shock treatments can also heighten calcium levels. To reduce high calcium, dilute the pool water with fresh water. Additionally, managing alkalinity can help control calcium hardness.

metal ladder leading to clear inground swimming pool

Cyanuric Acid (Chlorine Protector)

Understanding Pool Stabilizer

Pool stabilizer, also termed as pool conditioner, chlorine protector, or cyanuric acid (CYA), aids in preserving chlorine levels. It appears in forms such as stabilized chlorine (like dichlor or trichlor), liquid stabilizer, and powder stabilizer. When you utilize stabilized chlorine, no extra stabilizer is necessary.

Significance of Pool Stabilizer

Chlorine stabilizer functions like sunscreen for your pool, safeguarding chlorine from UV rays and thus retaining its strength. This enhances chlorine utilization throughout the swimming period, lowering chemical costs.

If you opt for a non-chlorine sanitizer, such as bromine, stabilizers are not needed.

Ideal Cyanuric Acid Levels

To maintain the effectiveness of chlorine in sanitizing your pool water, keep cyanuric acid levels between 30 and 50 ppm. Swim University recommends that free chlorine levels be 7.5% of your cyanuric acid levels.

Checking Stabilizer Levels

Testing might be necessary only at the beginning of the swimming season. Significant rainfall or high temperatures causing substantial evaporation can alter stabilizer levels.

Modifying Stabilizer Levels

Increase CYA levels by incorporating stabilized chlorine or cyanuric acid to your pool. Another option, as advised by The Spruce, is using baking soda as a pool stabilizer, which will also raise your pool’s alkalinity.

To diminish stabilizer levels, partially drain and refill the pool with fresh water.

Tips and Precautions

When embarking on a new venture, there’s invariably a learning phase. These additional recommendations and warnings from pool experts can assist you in mastering pool chemical management.

Wear safety gloves and goggles when handling pool chemicals, especially liquids.
Do not combine chemicals outside the pool.
Keep the pool pump and filter running when adding chemicals.
Introduce chemicals gradually; avoid overloading. More can be added if necessary.
Wait at least 20 minutes after adding a chemical before introducing another.
Allow at least an hour before re-testing and making more adjustments.
Based on the added chemical, wait between one and eight hours before swimming again.

Keeping Pool Water Safe

Ensuring balanced pool water chemicals creates a safe and enjoyable swimming space while also protecting your pool and its components.

With routine testing, you can spot and correct imbalances before they turn critical. Select the testing approach that works best for you, ensuring a safe and delightful swimming season.

Discover pool maintenance tools and fun swimming accessories like pool floats and water games at the Pool and Spa store at Christmas Central.