Is my pool leaking or evaporating?

Is my pool leaking or is it just evaporation?

Plenty of pool owners who reach out to us aren’t sure if they’re seeing a leak or just evaporation. Here’s an overview of the most common question we get: is it a leak, or just evaporation? 

If you want to find out for your own pool, get our pool leak guide. It has step-by-step instructions for diagnosing leaks so you know what you’re dealing with. 

Evaporation Explained

Evaporation rates for pools in Central Florida are affected by four primary factors. These factors are much higher in the cooler months than in the hotter months. That’s why you hardly notice evaporation in your pool during Florida’s hot summers. We know it’s counterintuitive, but it’s true!

Here’s a look at those 4 factors:

1. Humidity: Drier air has less humidity and in turn, can absorb more water from your pool’s surface. Our Florida summers are incredibly humid. But, if we get a few weeks of no rain in the summer, the humidity will drop and your pool’s evaporation will skyrocket. But because most every summer day has a heavy downpour, the air is saturated and cannot absorb more water.
2. Temperature: Warm temperatures in your pool water will give more energy to the water molecules, allowing them to more easily shift from their liquid state to their gaseous state.
3. Air Movement: If the humid air above a pool is moved and replaced with less humid air, this new less humid air can more easily absorb water from the pool surface. A pool in a courtyard, protected from the wind will see much less evaporation than a pool away from the house on a lake or golf course. Trees, fences, and other structures block the wind and as a result, reduce evaporation.
4. Surface Area: The more water being exposed to the air, the higher the evaporation. The more water features and waterfalls a pool has, the more evaporation it will see.

Examples

Imagine two pools, each 15,000 gallons but otherwise very different, belonging to two lovely Central Florida families, the Smiths and the Ramones.

The Smiths’ Pool:

• Seated away from the house, overlooking Lake Charmingman
• The view from the pool is clear from any trees or fences
• Solar heated
• 3 large rock waterfalls, running all day every day

The Ramones’ Pool:

• Seated in their quaint courtyard
• All sides blocked by the home itself or the fence that blocks the noise from RNR High School
• The pool isn’t heated
• The pool has no water features

Which will have more evaporation?

The Smiths’ Pool, undoubtedly. In the same season, with the same weather conditions, the Smiths’ pool will lose many times more water due to evaporation.

How many Evaporation Factors is your pool experiencing?

How much water should my pool lose to evaporation?

A great question, and it’s not that mysterious. 

If you are not running any kind of a heater, or any kind of water features, expect your pool to lose up to ¼” per day due to evaporation.

To dial in the estimate a little more, you can roughly add ¼” loss per day for every factor mentioned above. If your pool is solar heated, add ¼” per day. If you are running a water feature, add another ¼” of expected loss per day.

This estimate isn’t exact, but it can help you understand the impact evaporation will have on your pool’s water level.

How can I tell if my pool is experiencing a leak or just evaporation?

The process looks like this:

1. Fill the pool to the normal level, which is the middle of the skimmer face. Be careful not to overfill the pool, as the highest portions of most pool tile lines are not always water-tight (which is normal). 
2. Turn your pump off for a few minutes to allow the water surface to settle. You’ll need a flat and still water surface to draw an accurate starting line. 
3. Open your skimmer lid, and use a pencil to mark the current water level on the canister wall. This is your reference point.
4. Turn your pump back on and let it run as scheduled. This is day one of your test.
5. Let the pump run on its usual schedule for the next 48 hours. 
6. Turn your pump off for a few minutes to allow the water surface to settle, then use a ruler to measure the difference in inches between your pencil mark and the new water level. This represents your total water loss.

Or you can download our easy guide that walks you through this whole process. Get it here.