How to Balance Pool Water: The Easy, Complete Guide

It’s the key to making your swimming pool look great and last longer — not to mention enjoying it!

Read on, we’ll tell you how to balance pool water so it’s easy to understand!

Pool water balance means keeping the water “just right” so it’s safe to swim in, feels comfortable, and doesn’t harm the pool surfaces or equipment.

However, out of balance water can make swimming uncomfortable, and can also permanently damage the pool walls, deck, equipment and other surfaces around your swimming pool.

The top 3 key components to keep swimming pool water balanced are:

• Total Alkalinity
• pH
• Total Hardness (also known as Calcium Hardness).

These components must be “balanced” or, kept within their proper levels called their “ideal range.”

When these key components are balanced – within their proper levels – pool surfaces and equipment are protected from damage, and the sanitizer works effectively to keep the pool water clean, clear, and comfortable.

Simply stated, “balanced water” describes pool water’s ideal condition; it has just the right level of  Total Alkalinity, pH, Total Hardness and Total Dissolved Solids (TDS) in relationship to the water temperature.

The table below shows the optimal ranges for basic water chemistry:

Pool professionals use the Langelier Saturation Index (LSI) calculator. It gets a bit complicated, but if you’re interested, you can dive into it and find out if your swimming pool water is balanced by using the LSI calculator.

What Affects Water Balance?

Knowing what affects water balance is a key to understanding how to balance pool water.

Whether you own an in-ground or an above-ground pool, the same factors affect your pool water balance. These factors include frequent, heavy pool use, organic matter that gets into the water – leaves, grass or twigs – rainwater or flooding, water you fill your pool with to top it off, and even water temperature. Almost everything can alter the pool’s water chemistry.

However, these factors typically affect water balance the least!

The top 3 key factors that affect water balance are the levels and chemistry you’re constantly adjusting: Total Alkalinity, pH, and Total Hardness.

That’s why it’s essential to test your water regularly, and adjust these levels as needed to maintain them within their ideal ranges.

Why it’s Important to Balance Your Pool Water?

Essentially, balanced water means the water is not too acidic, not too alkaline and all the mineral levels are balanced. 

Water that’s too acidic can become corrosive, damaging pool surfaces and equipment. Plus, its harsh and irritating to swimmers. 

Pool water that’s too alkaline can cause scaling, which also damages pool surfaces and equipment, and is uncomfortable for swimmers.  

Balanced water is neither corrosive nor scaling. But here’s the thing: your pool water is constantly changing. It seeks its own level by dissolving and “holding” minerals until it becomes saturated, and cannot hold any more – that describes TDS.   

How Does TDS Affect Pool Water Balance?

TDS is the total of all dissolved solid matter in the pool water. That includes minerals, metals, salts, contaminants like lotions or cosmetics and the chemicals used to keep the water sanitized. In general, anything you put in the pool water that dissolves adds to the TDS level. 

You don’t need to check TDS levels as often as you check Total Alkalinity, pH and Total Hardness, but you will need to check them routinely – monthly is a good practice. 

The issue is that TDS builds up as pool water evaporates, and the minerals, particles, and chemical residues are left behind. High TDS can cause difficulty maintaining water balance, cloudy water, scale buildup, corrosion, and harsh water.  

TDS levels above 1,500 ppm will need to be addressed. The only way to remedy high TDS levels is to partially drain the pool and top it off with fresh water. Then, you’ll need to retest for TDS levels, and balance the Total Alkalinity, pH and Total Hardness levels. 

Swimming Pool Water too Acidic?

For example, pool water that doesn’t have enough minerals dissolved in it is typically more acidic and aggressive. It will attempt to saturate itself by dissolving everything it comes into contact with to build up its mineral content. The result: corrosion. Pool water will begin to corrode and etch away pool walls, surfaces, and anything metal, like ladders, screws, and underwater light fixtures. 

Swimming Pool Water too Alkaline?

Once pool water becomes fully saturated, it will attempt to lose any excess minerals, particles or material in the form of scale, which it deposits on whatever the water comes into contact with. Scale looks like white or tan deposits, films, or crystals.

Oversaturated pool water poses the greatest risk of scaling. It often looks cloudy and murky because of the excess particles floating freely in the water. If not corrected, scale can build up on pool filters, in pipes, pumps, decrease water circulation, and damage pool components.

Balanced water protects surfaces and water quality.

Testing pool water and keeping the key components in balance will keep it from becoming too acidic or too alkaline.

Knowing how to balance pool water, and keeping it balanced protects your pool surfaces and equipment from corrosion and scaling. Plus, water feels more comfortable and enjoyable to swim in.

Balanced swimming pool water also allows your pool’s sanitizer to work more effectively.

Sanitizing Your Swimming Pool

One of the biggest factors that influences a pool sanitizer’s ability to effectively clean the water is its pH level.

The ideal pH level should be between 7.2 – 7.8.

If pool water pH level is below 7.2, chlorine, as a sanitizer, dissipates much more quickly. That means you must add more chlorine. That costs more, plus, you spend more time adding chemicals to your pool water. And you may overchlorinate the water – resulting in itchy skin, red eyes and faded swimsuits.

On the other hand, if the pH level is higher than 7.8, chlorine loses its ability to sanitize the water. This also means you must use more chlorine to achieve the same chlorine concentration as a pool with a balanced pH level.

Here’s an example:

If the pH is 7.2, you add one dose of chlorine.

However, at a pH of 8.2, chlorine concentration can only reach 15%, so you need to add more to achieve the same chlorine concentration.

At a pH of 8.2 you would need to add 5x the amount of chlorine you’d add at a pH of 7.2.

The Secret to Clean, Clear Water: Keep it Balanced

Constantly balancing and sanitizing your swimming pool can seem like a lot of work, especially if you don’t use the pool consistently.

However, testing and adjusting it regularly shouldn’t take much time. Simply keeping your pool’s water chemistry balanced and the sanitizer level in check can help your pool last even longer. It can also save you the hassle and expense of replacing broken pool equipment or resurfacing your pool deck or pool walls.

And best of all, swimming will be much more enjoyable – no more itchy skin or red eyes.