Maintaining balanced pool water chemistry in your fiberglass pool is truly a balancing act. Each of the six factors that calculate the Langelier Saturation Index (LSI) can ebb and flow, although some are more reactionary and volatile than others. While maintaining all six factors may feel like a juggling act, understanding what they are, how they interact, and their impact on your pool is critical to keeping the LSI balanced and your water in equilibrium.

The Critical Role of pH

pH, or “potential of hydrogen,” is the most critical variable in water chemistry balance. While alterations of any involved equation variables can affect your water balance, a change in pH can have ten times the effect compared to other LSI factors. 

pH levels indicate water’s acidity or basicity. They range from 0 to 14, with 0 being very acidic, 7 being neutral, and 14 being very basic. Chlorine and other sanitizers will only remain effective and function correctly within specific pH ranges—namely, the range between 7.2 and 7.4 deemed ideal for swimming pools. Hydrochloric or muriatic acid can lower high pH levels, while a low-pH pool will need an alkaline boost from sodium carbonate. 

The best thing an owner can do for the health and safety of their pool and its frequent swimmers is to regularly test the pH and other chemical levels. Daily testing and checks before and after each use are recommended and will help you become more familiar with how various factors, including some outside your control, affect your pH and overall LSI levels. 

Total Alkalinity

Alkalinity is often called “the yin to pH’s yang,” as the two are related. Alkalinity measures water’s capacity to withstand changes in pH. In fiberglass pools, recommended total alkalinity levels range from 80 to 120 parts per million.

Low alkalinity makes water corrosive, causing stains and etching on your pool’s surface. Water will become depository if alkalinity rises above the recommended range for fiberglass pools (120 ppm). As a result, pool surface scaling occurs and a white cloudy film may appear, clogging filters and reducing circulation.

Total Dissolved Solids (TDS)

As the name implies, total dissolved solids (TDS) include chemicals or anything other than calcium that remains after water evaporates. These solids can include salts, metals, minerals, and other organic materials that have entered and dissolved within the pool water. We recommend that the TDS level be no higher than 1,500 ppm (or 1,000 ppm above safe salt level in saltwater pools). A high TDS level can lead to algae blooms, scaling, or other pool stains.

Cyanuric Acid (Chlorine Stabilizer)

Cyanuric acid (CYA) will prevent the sun’s ultraviolet rays from decomposing free chlorine in your pool water. Levels between 30 and 50 ppm are recommended, but higher levels don’t necessarily mean better results. If the cyanuric acid level reaches 100 ppm or above, chlorine’s effectiveness at killing bacteria and algae is compromised.

Calcium Hardness

A lower calcium hardness level in your pool water results in a softer and silkier it will feel on swimmers’ skin. Calcium hardness is also essential for maintaining water cleanliness and equipment operation. Regulated calcium hardness of less than 120 ppm will help keep pool materials looking and working their best. When calcium hardness is too low, the water becomes aggressive and corrosive. When too high, pH levels raise, leading to cloudy water, surface discoloration, and filter-clogging calcium deposits.

Temperature

The temperature factor is the only non-chemical component of water chemistry balance and your pool’s LSI. Utilizing a pool heater will make your temperature factor much easier to control. Many swimmers enjoy a “bathwater” feel and temperature, but water warmer than 82 degrees Fahrenheit can encourage bacteria or algae growth. Calcium deposits form more quickly in warmer water, while a too-cool pool makes it easier for water to begin corroding equipment.

Parents of infants and young children should consider keeping temperatures slightly higher into the upper 80s. However, a pool used primarily for exercise or competitive swim training should skew lower, between 77 and 82 degrees Fahrenheit. A good general rule for many pool owners is aiming for a water temperature between 77 degrees and the mid-80s. Keeping a constant temperature will help prevent bacteria and algae growth and improve the efforts of chlorine, saltwater, or other pool sanitation measures.

Every Factor is Important

Many pool owners and even pool service professionals habitually test for pH and chlorine, and occasionally they check the alkalinity. However, this approach ignores many critical LSI factors. Although they do not tend to change as rapidly, You should also regularly test calcium hardness, CYA, and TDS. By testing all six factors in your pool water, you will have a more clear and complete understanding of its LSI and water balance.

Balancing your pool water is essential for maintaining its clarity, safety, and longevity, especially for fiberglass pool owners. While pool water chemistry balance may seem complex, modern tools like the Orenda Technologies LSI Calculator have simplified the testing and adjustment process. This blog post will guide you through using Orenda’s app to achieve optimal water balance in your pool, ensuring it stays in beautiful condition without needing a degree in chemistry. We’ve included step-by-step instructions, complemented by screen-capture images, to make the process as straightforward as possible.

Editor’s Note: There are available alternatives to the Orenda app. Thursday Pools and Orenda have no relationship other than sharing a desire to help fiberglass pool owners properly maintain their water chemistry. If you want to get even more informed on water balance and related topics, check out Orenda’s library of educational videos, tutorials, and other resources. 

Step 1: Download the Orenda App

The journey to balanced pool water begins with a simple download of the Orenda app, available on both iOS and Android platforms. This app significantly simplifies pool chemistry, particularly focusing on the Langelier Saturation Index (LSI), making it an indispensable tool for pool owners.

Step 2: Input Your Pool Details

Once you have downloaded and opened the app, the first step is to input your pool’s specific details, such as the volume of your pool in gallons and the water temperature, which are critical for accurate calculations. The app’s user-friendly interface guides you through entering these initial details.

Step 3: Enter Current Water Chemistry Levels

The next step involves inputting the current levels of various water chemistry variables that influence your pool’s LSI.

These include: 

• Water temperature
• pH level
• Calcium Hardness
• Total Alkalinity
• Cyanuric Acid stabilizer
• Total Dissolved Solids

You’ll find a section on the left-hand side of the app dedicated to entering these values. Precise measurements at this stage are crucial for accurately assessing your pool’s water balance. 

Also, note that the app includes levels for Chlorine and Phosphates. While these values don’t affect the LSI, they are essential in maintaining a healthy and safe pool.

Step 4: Adjusting for Optimal LSI

After entering your pool’s details and current chemistry levels, the real magic begins. The app allows you to tweak and adjust the values on the right-hand side of the screen to see how changes can affect your pool’s LSI. 

The goal is to adjust these levels until you achieve a desired LSI value within the optimal range of -0.3 to +0.3. Note that for saltwater pools, we recommend a slightly tighter range of -0.2 to +0.2 to account for the unique chemistry of saltwater systems.

The app’s LSI indicator is highlighted in different colors depending on the status. 

•   Over +0.30 is coded PURPLE, meaning your water can cause scaling on your equipment and gelcoat surface. 
• -0.30 to +0.30 is coded GREEN to indicate the ideal LSI balance. 
• -0.30 to -0.01 is YELLOW, meaning you’re close to balance but not quite there. 
• < -0.30 is coded RED to alert you to corrosive water that can damage your pool equipment and gelcoat surface.

The ideal target is as close to zero as possible. This interactive feature allows you to experiment with different adjustments to understand how each factor may affect your pool’s overall balance.

Step 5: Calculate and Correct

After adjusting your inputs to reach the ideal LSI range, hitting the “Calculate” button creates a customized list of actions and products needed to balance your pool water. It tells you what needs to be adjusted and recommends specific chemicals and quantities to achieve the desired balance. This step eliminates guesswork, ensuring you use the right products in the right amounts.

Step 6: Implement Recommendations

With a tailored action plan, the final step is implementing the app’s recommendations. Whether adjusting the pH, adding calcium hardness increaser, or balancing total alkalinity, follow the guidelines to bring your pool water into harmony.

Why Use the Orenda App?

Simplifies Complex Calculations

The Orenda app demystifies the complexity of water chemistry, breaking it down into simple and manageable steps. This guidance ensures that pool owners can maintain their pool’s health without needing deep technical knowledge.

Saves Time and Money

By providing precise recommendations, the app helps pool owners avoid over- or under-treating their pool, saving money on chemicals and preventing potential damage to the pool’s surface or equipment.

Enhances Pool Enjoyment

Regularly using the Orenda app to balance your pool water means clearer, safer water and a more enjoyable swimming experience for you and your family. It also extends the lifespan of your pool by preventing damage and other issues related to imbalanced water.

Balancing your pool water using the LSI doesn’t have to be daunting. With the Orenda Technologies LSI Calculator, achieving and maintaining optimal water balance is easier and more intuitive than ever. By following the simple steps outlined above and taking advantage of the app’s smart recommendations, you can ensure your pool remains an enjoyable oasis for years to come.