What Is Balanced Pool Water? The LSI

Balanced Water Chemistry Involves More Than Just Chlorine and Acid.

There's More To Chemistry Than Meets The Eye.

It's invisible, But The Effects, Good Or Bad, Will Be Noticeable.

What Is balanced pool water: LSI — This Pool Water Should Be Balanced. Right?

Introduction

If you are trying to take the best care of your pool, you know that balanced pool water is a must. When researching balanced pool water you might have come across the term LSI – the Langelier Saturation Index. It might sound like a complex concept, but understanding LSI is crucial for the overall health of your pool. LSI plays a key role in maintaining its appearance to ensure the longevity of surfaces and equipment. Let's dive into the details to grasp why LSI matters so much for the well-being of your pool.

WHAT is Balanced Pool Water: LSI

Named after chemist Wilfred Langelier, the Langelier Saturation Index is a calculated parameter that evaluates the balance of your pool water. Water has two methods of balancing: "eating" (etching, corrosive water) and "dumping" (scale forming). The LSI provides insights into where we can correct water balance to prevent water from eating and dumping. The LSI considers six factors:

1. pH

2. Carbonate Alkalinity

3. Calcium Hardness

4. CyA (Cyanuric Acid)

5. Water Temperature

6. Total Dissolved Solids (TDS/Salt)

Some definitions include a seventh factor: Borates.

The LSI number is used to determine: 1. whether your pool water is in balance, 2. tends towards being corrosive (eating), or 3. is prone to scale formation (dumping).

The Balanced Pool Water Equation

LSI isn't just a single number or even a range of number; it's an equation. To oversimplify things, there are four ranges of results to this equation:

1. A result of 0.00 means your pool water is in perfect balance.

2. A result of -0.30 to -0.01 can be considered an acceptable balance.

3. A result above 0.30 means your water tends to form scale.

4. A result of -0.30 or less indicates a tendency towards corrosiveness.

WHY Balanced Water Matters: LSI Adjustments

Keeping the LSI balance right is crucial for several reasons:

Corrosion Prevention: If your pool water is "hungry" (low LSI), it can "eat" (corrode, etch) surfaces and metal components, leading to equipment deterioration and costly repairs. Corrosion & etching can not be fixed.
Scale Formation: On the flip side, if your water is "full" (high LSI), it can "dump" scale onto surfaces and equipment, impacting system efficiency and aesthetics. Scale can be fixed via cleaning or chemicals.
Comfort and Safety: Balanced water minimizes skin and eye irritation, provides a more comfortable swimming experience, and ensures effective pool sanitization.
Equipment Longevity: Maintaining the right balance extends the lifespan of your pool equipment, saving you money in the long run.

HOW to Balance Water: Adjusting The LSI

If your pool's LSI is off, here are some strategies to bring it back in line:

Adjusting pH: The ideal pH range may vary, but controlling alkalinity before adjusting pH helps prevent corrosive water chemistry.
Managing Alkalinity: Regularly check and adjust pool alkalinity to stabilize water conditions.
Calcium Hardness: We have been brainwashed into thinking Calcium Hardness needs to be kept down for water to be balanced; this may not always be the case. We need to adjust calcium hardness (sometimes up to 400 ppm) for a balanced pool, especially in areas with soft water.
CYA & Partial Draining: High Cyanuric acid levels may require partial water draining to maintain chlorine efficacy. CYA also affects pH and alkalinity.
Phosphate Purge: Though not directly related to the LSI, controlling phosphate levels is crucial to prevent algae growth and optimize chlorine performance.
Enzymes: As with the Phosphate Purge, Enzymes do not directly impact the LSI. However, adding enzymes helps in contaminant removal, enhancing chlorine effectiveness.

What Is Balanced Water: LSI — The Orenda Calculator

The best thing you can do for your pool is to balance your water. To help you with this we recommend downloading the ORENDA POOL CHEMICAL DOSING CALCULATOR. This is a free, easy-to-use app that we at SWIMCLEAR POOLS use for all of our pools, and we suggest you use it, too.

To learn more about the LSI, please visit the Orenda Blog.

Conclusion

LSI is the key to a balanced, efficient, and visually pleasing pool. Regularly monitoring and adjusting LSI ensures a pristine-looking pool and a safe and enjoyable swimming environment. Consider checking your LSI at least once a month (ideally every week) to keep your pool in top shape. If you have any questions about your pool water, feel free to reach out – happy swimming!