Owning a pool is a dream come true for many homeowners. The glistening water, the laughter of family and friends, and the sense of relaxation are all part of the appeal. However, achieving and maintaining a pristine pool isn’t just about filling it with water and adding chlorine. It’s a delicate balance between sanitation and water chemistry, backed by proper circulation, filtration, and maintenance. In this blog, we’ll delve into the basics of water chemistry for new pool owners, emphasizing the crucial relationship between sanitation and water balance.
Sanitation: More Than Just Chlorine
The first misconception many new pool owners have is that chlorine alone will keep their pool clean and safe. While chlorine is indeed a vital component of pool sanitation, it’s not a standalone solution. The effectiveness of chlorine depends on maintaining the correct pH levels and ensuring the Cyanuric Acid levels are just right.
pH Levels: pH measures the acidity or alkalinity of the water, with 7.4 to 7.6 being the ideal range for pool water. When the pH is too high, chlorine becomes less effective, and when it’s too low, it can corrode pool equipment and irritate swimmers’ skin and eyes.
Cyanuric Acid: Also known as a stabilizer or conditioner, helps protect chlorine from the UV rays from the sun. The ideal range is 30 – 50 ppm. Levels below 30 ppm will result in the UV rays from the sun quickly deactivating all residual chlorine in the pool. If the levels are above 50 ppm cyanuric acid will overprotect the chlorine and prevent it from properly sanitizing the water. If cyanuric acid levels reach 100 ppm, the water should be lowered or completely drained and refilled with fresh water.
Water Balance: The Key to a Truly Healthy Pool
Along with having a properly sanitized pool, other factors play a key role. Water balance is key in maintaining a pool that is truly healthy. There are 5 factors used to determine if pool water is balanced: pH, Total Alkalinity, Calcium Hardness, Water Temperature and Total Dissolved Solids (TDS). The most widely used calculator for determining if the water is balanced is the Langelier Saturation Index (LSI) Langelier Saturation Index Calculator
pH Level: pH measures the acidity or alkalinity of the water, with 7.4 to 7.6 being the ideal range for pool water.
Alkalinity: Alkalinity acts as a buffer for pH, helping to keep it stable. A proper alkalinity range is 80-120 ppm (parts per million).
Calcium Hardness:This refers to the amount of dissolved calcium in the water. Maintaining calcium hardness between 200-400 ppm helps prevent water from becoming corrosive.
Water Temperature: While the water temperature is an important factor in determining if the water is balanced, temperature is not a factor that is typically adjusted to bring water into proper balance.
Total Dissolved Solids (TDS):Total dissolved solids is a measure of the total concentration of solids in the water, expressed as ppm. Dissolved solids come from one of three main sources: fill water, treatment chemicals and swimmers. TDS builds over time and the only way to reduce it is to drain some or all of the water and refill with fresh.
Circulation and Filtration: The Heart of Pool Maintenance
To maintain clean and clear pool water, you need excellent circulation and filtration. This means ensuring that water flows consistently and efficiently through the pool’s system, including the skimmer, main drain, pump, and filter.
Skimmer: The skimmer is your first line of defense against debris and contaminants. Regularly emptying the skimmer basket and cleaning it will ensure it functions optimally. 75% of the water drawn into the filtration system comes from the skimmers because most of the contaminants in a pool live at the surface.
Main Drain: The main drain sits in the bottom of the pool at the deepest point. It is critical in pulling water into the filtrations system from the bottom of the pool. 25% of the pools’ water should be drawn from the main drain.
Pump: The pool pump is the heart of your pool’s circulation system. Regular cleaning and maintenance are crucial. Ensure the pump basket is free of debris and in good repair. Even the smallest crack in a pump basket can lead to costly consequences such as having to replace the pool pump.
Filter: Pool filters come in three main types—sand, cartridge, and diatomaceous earth (DE). Regardless of the type, they all need routine cleaning and maintenance to keep the water clear.
Determining Pool Size and Turnover Rate
One of the often-overlooked aspects of pool maintenance is knowing the exact volume of water your pool holds. Astonishingly, estimates suggest that 70-75% of homeowners don’t know how to properly measure their pool’s gallons. This knowledge is essential because it directly impacts how long your pool pump should run and the amount of chemicals needed to maintain a healthy pool.
Step 1 – Measure the length of your pool
Step 2 – Measure the width of your pool
Step 3 – Calculate the average depth of your pool
(Shallow end depth + Deep end depth) ➗ 2 ＝Average depth
Step 4 – Length X Width X Average Depth X 7.5 = Gallons of water in the pool
*For odd shape pools, measure the pool in sections, determine the amount of water in each section then add the gallons of all the sections together.
Turnover Rate: Is the amount of time, measured in hours, that it takes to move an amount of water equal to the gallons of water in the pool through the filtration system one time. However, According to the Gage-Bidwell Law of Dilution, water that is recirculated (turned over) one time has only filtered 63% of the water in the pool. After two turnovers 86% is achieved. Three turnovers achieves 95% and four achieves 98%. The law goes on to state that to achieve 99.99%, the pool must turn over ten times. While a public pool is required by code to turn over four times per 24 hour period, due to far fewer swimmers, a residential pool should turn over two times per 24 hours. Gage-Bidwell Law of Dilution
To calculate the turnover rate, it’s important to know how many gallons of water your specific pool pump can move per minute (flow rate). That information can be obtained by adding a flow meter to your pool system or through some testing to determine the system’s Total Dynamic Head and convert to gallons per minute using the manufacturer’s pump curve chart.
Once you determine the flow rate of your pump, you can now calculate the turnover rate.
Pool Gallons ➗ Flow Rate ➗ 60 = Turnover Rate
For instance, if your pool is 25,000 gallons and your pump flow rate is 70 GPM
25,000 ➗ 70 ➗ 60 = 5.95 hours to turn your pool over one time.
To achieve the required two turnovers, simply double that time. In the above example I would need to run my pump twelve hours per day ensuring effective circulation and filtration. .
Achieving the Perfect Chemical Balance
Maintaining the proper chemical balance in your pool is an ongoing process. Regularly testing your water and making necessary adjustments is crucial for water clarity and swimmer comfort.
Here are some tips to help you achieve and maintain that balance:
Invest in a quality water testing kit or test strips to check your pool’s chemical levels regularly. Free water tests are done at your nearest Poolwerx location if you want to leave this to the professionals.
Make sure your Alkalinity is always within the correct parameters as this will affect the ability to manage your pH. Test at least weekly.
Balance your pH levels as this affects the effectiveness of sanitizing chemicals as well as the acidic or alkaline nature of the pool water. Test at least weekly.
Keep your chlorine levels within the recommended range, typically 1-3 ppm (parts per million). Test at least weekly. You must ensure the chlorine level never drops to zero.
Adjust calcium hardness level monthly as needed to keep it within the desired ranges.
Shock your pool periodically to eliminate organic contaminants and maintain chlorine effectiveness. Even if your pool is a salt pool, it will still require occasional shocking with chlorine or a non-chlorine based shock treatment.
In summary, being a responsible pool owner involves much more than just filling your pool with water and adding chlorine. Achieving and maintaining crystal-clear pool water requires a deep understanding of water chemistry, coupled with proper circulation, filtration, and diligent maintenance. Remember to determine your pool’s volume, adhere to the law of dilution, and regularly test and adjust your pool’s chemical balance.
If you ever feel overwhelmed or need professional assistance with your pool maintenance, don’t hesitate to contact your nearest Poolwerx location or book a service. We have the expertise to keep your pool in great shape, ensuring you make the most of your pool ownership experience.