Using Chlorine to Sanitize Swimming Pools Effectively

Using Chlorine to Keep Pools Clean and Sanitized

Chlorine is the most common sanitizer used for swimming pools. When used properly, chlorine kills harmful bacteria, algae and microorganisms that can contaminate pool water. While chlorine has some drawbacks, its ability to effectively kill germs makes it an important part of pool maintenance.

Benefits of Using Chlorine in Pools

Here are some of the top advantages of using chlorine as a pool sanitizer:

• Kills bacteria - Eliminates disease-causing microbes like E. coli.
• Prevents algae - Keeps green, black and mustard algae from growing.
• Destroys organic matter - Gets rid of contaminants from swimmer's body oils, sweat, etc.
• Provides residual sanitizing - Continues working between shock treatments.
• Is inexpensive - Tablets, powders and liquids are affordable sanitizing options.
• Is easily measurable - Chlorine levels are simple to test with kits.
• Works quickly - Rapidly kills microbes when levels are adequate.

When used properly, chlorine is effective at protecting swimmers from illness-causing germs in pool water.

How Chlorine Sanitizes Pools

Chlorine sanitizes pool water through a process called oxidation. Here's how it works:

1. Forming Hypochlorous Acid

When chlorine is added to pool water, it combines with the water (H2O) to form hypochlorous acid (HOCl). This acidic solution is the primary sanitizing agent.

2. Killing Bacteria and Microbes

The hypochlorous acid works to destroy disease-causing microorganisms, bacteria and algae in the pool water.

3. Oxidation Process

The chlorine oxidizes and destroys the cell walls and structures of organisms it comes into contact with in the pool.

4. Removal of Contaminants

This oxidation process removes organic waste matter, sweat, urine and other pollutants brought into the pool by swimmers.

5. Providing Residual Protection

Some residual chlorine remains active in the water to continue sanitizing until the next chlorine addition.

Understanding this oxidation process helps pool owners maintain proper chlorine levels for clean, safe water.

Types of Chlorine Used in Pools

There are several different types and forms of chlorine that can be used to sanitize swimming pools:

1. Sodium Hypochlorite

- Liquid bleach solution

- 10-15% available chlorine

- Fast dissolving and quick sanitizing

2. Calcium Hypochlorite

- White powder or tablets

- 65-75% available chlorine

- Longer lasting; chlorine release is slower

3. Lithium Hypochlorite

- Granules or tablets

- 35% available chlorine

- Higher solubility for fast dissolving

4. Chlorinated Isocyanurates

- Stabilized tablets or powders

- 60-85% available chlorine

- Provides stable chlorine levels

5. Bromine

- Two-part tablets with bromine and chlorine

- Slower dissolving long-term sanitizing

Each chlorine type has advantages and ideal uses. Choose an appropriate product based on pool size, usage, and local conditions.

Ideal Chlorine Levels for Pool Sanitization

Maintaining proper chlorine levels is crucial for clean, sanitized pool water. Recommended free chlorine levels are:

• 1-3 ppm for residential pools
• 3-5 ppm for public or commercial pools
• Spas may require 2-4 ppm

Test chlorine levels regularly using reliable test strips or liquid kits. Adjust as needed to stay within ideal parameters.

Factors That Affect Chlorine Levels

Many variables influence ideal chlorine concentrations. Higher levels may be needed for:

• Public or heavily used pools
• Hot tubs or spas
• Cloudy water or algae growth
• Higher bather load and contaminants
• Warmer climates and temperatures
• Frequent rain or splash out
• Higher sunlight intensity

Consider local conditions and adjust chlorine to maintain cleanliness. Shock at dusk after heavy use.

Adding Chlorine to Pools

Chlorine can be added to pools in several ways:

1. Skimmer

- Add chlorine tablets or powders to skimmer baskets for gradual dissolution.

2. Automatic Feeder

- Use an inline feeder or floating dispenser to automatically dispense chlorine.

3. Manual Dosing

- Directly add liquid bleach around pool edges and let circulate.

4. Large Stabilized Tablets

- Place in floats, feeders or chlorinators for extended sanitizing.

5. Shock Treatment

- Periodically shock the pool to maintain chlorine levels.

Use a combination of regular chlorination methods plus periodic shocking as needed. Follow safety guidelines when handling chlorine.

Shocking Pools with Chlorine

Shocking helps maintain sufficient chlorine levels. There are two main approaches:

1. Superchlorination

- Temporarily raises free chlorine to 5-10 ppm.

- Destroys built-up contaminants.

- Use when pool water looks hazy or dirty.

2. Breakpoint Chlorination

- Ultra-high chlorine level of 10-20 ppm.

- Burns offchloramines and dissolved waste.

- Best for public pools after heavy use.

Shock the pool weekly or as needed, and always after heavy bather loads. Shock at sundown and let circulate overnight.

Side Effects of Chlorinated Pools

Using chlorine does come with some side effects and drawbacks:

Skin and Eye Irritation

- Red eyes, dried skin.

Respiratory Irritation

- Coughing, sneezing.

Chloramine Formation

- Byproduct when chlorine binds with swimmer contaminants.

Corrosion and Damage

- Can degrade pool surfaces and equipment over time.

Chlorine Odor

- Strong smell, especially when levels get too high.

Maintaining proper chlorine levels can help minimize adverse effects. Adequate circulation and ventilation also helps.

Improving Pool Water Balance

Balanced water chemistry optimizes chlorine effectiveness while reducing side effects. Ideal levels:

• pH: 7.2-7.6
• Total Alkalinity: 60-120 ppm
• Calcium Hardness: 200-400 ppm

Test water 1-3 times a week and adjust as needed. Quality test kits are essential for proper monitoring and maintenance.

Alternatives to Chlorine

Other pool sanitizing options include:

Bromine

- Also an effective sanitizer.

- At 2-4 ppm ideal level.

- Less irritating than chlorine for some.

Ionizers and Generators

- Use metal ions like copper and silver to sanitize.

- Require low salt levels.

- Reduce the need for chlorine.

Ozone

- Ozone gas injections sanitize pool water.

- No chemical residuals.

- Often used with lower chlorine levels.

UV Light

- UV systems kill microbes as water flows past lamps.

- Requires very low chlorine levels.

- Installation can be complex.

Discuss these alternatives with pool experts to see if they could work for your pool.

Safety Tips for Using Chlorine

Follow these tips for safe chlorine handling and usage:

• Read labels and follow usage directions.
• Store chemicals properly in cool, dry place.
• Wear gloves and eye protection.
• Add to water rather than vice versa.
• Don't mix chlorine types or chemical products.
• Rinse skin after handling.
• Avoid breathing in fumes.
• Keep pets and children away from chemicals.

With proper usage, chlorine can make pool water clean and inviting all season long. Be sure to use good ventilation and give chlorine time to circulate fully after adding.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.