How Do I Prevent Evaporation in My Pool?

Use a pool cover when the pool is not in use and maintain consistent water temperatures.

Why Does Pool Evaporation Happen?

Evaporation occurs when water turns into vapor and escapes into the air. Several factors influence the rate of evaporation, including:

• Temperature: Warmer temperatures speed up water evaporation.
  

• Humidity Levels: Low humidity causes faster evaporation as dry air absorbs more moisture.
  

• Wind Exposure: Strong winds remove surface water, increasing evaporation rates.
  

• Sunlight: Direct sunlight heats the water and speeds up evaporation.
  

Signs Your Pool Is Losing Water Due to Evaporation

• Water levels drop even when there are no visible leaks.
  

• You notice increased water refills throughout the week.
  

• Chemical levels fluctuate more frequently.
  

• Pool covers appear damp from water vapor condensing.
  

How to Prevent Pool Evaporation

1. Use a Pool Cover

A pool cover is one of the most effective ways to reduce evaporation. By covering the pool when not in use, you can:

• Reduce evaporation by up to 90%.
  

• Retain heat, lowering energy costs for heated pools.
  

• Prevent debris from entering the water, reducing maintenance time.
  

There are different types of pool covers to consider:

• Solar Covers: Use the sun’s energy to warm the water while reducing evaporation.
  

• Automatic Covers: Provide convenience with easy operation.
  

• Winter Covers: Protect pools during off-seasons.
  

2. Install a Windbreak

Wind significantly increases evaporation. To minimize this effect, consider installing:

• Fences: A solid fence around your pool can act as a wind barrier.
  

• Hedges and Shrubs: Natural barriers that block wind while enhancing aesthetics.
  

• Screen Enclosures: Provide additional protection from wind while keeping debris out.
  

3. Reduce Water Temperature

If you use a pool heater, keeping the temperature too high can accelerate evaporation. To prevent this:

• Set your pool heater to 78-82°F to balance comfort and water retention.
  

• Turn off heating when the pool is not in use.
  

• Use a solar cover to trap heat without excessive evaporation.
  

4. Use a Liquid Solar Cover

Liquid solar covers are an alternative to traditional pool covers. These chemical-based covers create a thin, invisible layer on the surface that slows down evaporation. Benefits include:

• Easy application, just pour into the water.
  

• Works even when the pool is in use.
  

• Reduces evaporation by up to 50%.
  
  

5. Maintain Proper Water Chemistry

Maintaining balanced pool chemistry can indirectly help reduce evaporation by stabilizing water conditions. Key factors to monitor:

• Chlorine Levels: Prevents bacteria growth, reducing the need for excessive refilling.
  

• pH Balance: Keeps water from becoming too acidic or alkaline.
  

• Alkalinity: Helps maintain water stability.
  

6. Add Shade Structures

Blocking direct sunlight helps reduce both evaporation and heat gain. Consider installing:

• Pergolas: Stylish structures that provide partial shade.
  

• Shade Sails: Flexible, easy-to-install fabric covers.
  

• Umbrellas: Portable and adjustable shading solutions.
  

7. Limit Water Features

Waterfalls, fountains, and spillovers increase surface area, leading to faster evaporation. To minimize water loss:

• Turn off water features when not in use.
  

• Use a timer to limit operation during peak heat hours.
  

• Adjust the flow rate to reduce excessive splashing.
  
  

8. Refill Only When Necessary

Refilling your pool frequently can disrupt chemical balance and contribute to higher evaporation rates. Instead:

• Monitor water levels weekly to detect abnormal losses.
  

• Refill during cooler times of the day (early morning or late evening).
  

• Avoid overfilling beyond the recommended level.
  

9. Use Pool Covers Overnight

Nighttime evaporation is a common issue, especially in dry climates. Covering your pool overnight helps retain moisture and reduces the need for frequent refills.

10. Optimize Pool Placement (For New Pools)

If you're building a new pool, consider strategic placement to reduce evaporation:

• Position the pool in an area with natural wind protection.
  

• Use surrounding landscaping to provide shade.
  

• Avoid placing the pool in a completely open, exposed area.
  
  

How Much Water Can You Save?

Implementing these strategies can significantly reduce evaporation. Here’s how much water you can save annually based on common prevention methods:

• Pool Cover: Saves up to 10,000 gallons per year.
  

• Liquid Solar Cover: Saves approximately 5,000 gallons annually.
  

• Windbreaks and Shade: Reduces water loss by 30-40%.
  
  

What to Do If Water Loss Persists

If you’ve tried these methods and still experience significant water loss, consider checking for leaks. Here’s how:

1. Perform a Bucket Test: Place a bucket of water on the pool step and compare water levels after 24 hours.
   

2. Inspect the Pool Liner and Plumbing: Look for visible cracks or wet spots around the pool.
   

3. Call a Pool Technician: If you suspect a leak, professional inspection is recommended.
   
   

Keep Your Pool Water Where It Belongs

Preventing evaporation not only saves water but also reduces maintenance and chemical costs. By using pool covers, windbreaks, shade structures, and optimizing water features, you can significantly slow down water loss. Consistently monitoring water levels and making small adjustments can keep your pool running efficiently all season long.