Imagine your pool on a hot summer’s day—its shimmering water beckoning you to take a refreshing plunge. However, the same relentless sun that makes your pool so inviting can also lead to a common concern among pool owners: evaporation. In this blog post, we’ll dive into the world of pool evaporation, exploring its causes, prevention measures, and smart solutions to help you keep your pool water levels in check.

Unveiling the Science of Pool Evaporation
Pool evaporation is the natural process by which water turns into vapour due to exposure to the atmosphere. It occurs when water molecules at the surface of the pool gain enough kinetic energy from the surrounding environment (typically from sunlight and warmth) to break their bonds and transition from the liquid phase to the gas phase. This transition is what we refer to as evaporation. Several factors contribute to this phenomenon:

Heat: Higher temperatures, especially during the summer months, accelerate evaporation. For every square metre of the pool area – an average of 7.6-7.9 mm of water is lost to evaporation in a day in Queensland from December to January. For example, a 9.2M X4.5M pool (41.4M2 surface area, water capacity of approx 53,820L) in Brisbane would lose 51,638 litres from October to March, an average per month of 8,606 litres. Although evaporation rates are lower during the cooler six months of the year, it never stops.

Humidity: Low humidity levels encourage faster water evaporation. Relative humidity is a measure of how much moisture the air contains compared to the maximum moisture it can hold at a given temperature. When the relative humidity is low, the air is relatively dry and can absorb more moisture, which includes water from your pool. In such conditions, the rate of evaporation from the pool’s surface will be higher because the dry air “pulls” moisture away from the water.

Wind: Wind can also increase the rate of evaporation from your pool. A gentle breeze can carry away the moist air right above the pool’s surface and replace it with drier air, enhancing the evaporation process. The bigger the pool, the more surface area, therefore, a greater evaporation volume.

Pool Size and Shape: Larger and more exposed pools tend to experience greater evaporation rates.

Preventing Pool Evaporation

While you can’t stop evaporation entirely, you can minimize its effects through these proactive measures:

Pool Covers: Using a pool cover when the pool is not in use is one of the most effective ways to prevent evaporation. A well-fitted cover creates a physical barrier that reduces exposure to the atmosphere, significantly decreasing the rate of evaporation and helping to conserve water.

Windbreaks: Installing windbreaks, such as privacy screens or landscaping features, can shield your pool from strong winds, reducing evaporation.

Maintain Proper Water Chemistry: Balanced water chemistry can help slow down evaporation. Regularly test and adjust pH, alkalinity, and calcium hardness. While balanced water chemistry can indirectly contribute to water conservation by reducing the need for water replacement, it is important to note that it won’t have a direct impact on the rate of evaporation.

Reduce Heat Loss: Maintain the pool water at lower temperatures when possible, as warmer water evaporates more quickly. When you are running a heater it is good to keep in mind warmer water has more energy, and the water molecules at the surface gain energy faster, increasing the likelihood of them transitioning from a liquid to a gas (evaporating)

Monitor Water Levels: Keep an eye on your pool’s water level and top it up as needed to prevent it from dropping too low.

Solutions for Managing Evaporation: If you’re dealing with ongoing evaporation issues, consider these practical solutions:

Efficient Pool Pumps: Invest in an energy-efficient pool pump with variable-speed settings to reduce the need for constant circulation. Madimack is the leader in this field at the moment with cost-effective and user friendly options. Madimack pumps:

Another option is to install The Inverter Plus, Madimack’s latest energy saver.  It is a ‘plug’n play’ variable speed controller for backyard swimming pool pumps; turning an energy-guzzling single-speed-pool pump into an efficient variable-speed-pool pump.  This innovative unit is simply retrofitted to an existing single-speed-pool pump, producing up to 80% instant energy & cost savings. Single-speed-pool pumps are installed in over 70% of Australian pools (residential and commercial).  With the introduction of Variable Speed Drives (VSD) to pool filtration systems, the energy and cost benefits produced are enormous, crucially benefiting “net-zero” carbon markers.

Rainwater Harvesting: Consider collecting rainwater in a storage tank and using it to top up your pool, reducing the need for tap water. Always be mindful that by adding rainwater you are adding phosphates that will need to be treated by a phosphate removed. When rain falls, it can pick up contaminants present in the atmosphere, such as dust, pollen, leaves, and airborne pollutants. This collected rainwater can carry these contaminants into your pool when it lands in or around it. Once phosphates are introduced into the pool water, they can contribute to various pool water problems. Phosphates serve as a nutrient source for algae, potentially leading to algae blooms if the phosphate levels are high. Algae growth can then lead to poor water quality, increased chemical usage, and the need for more frequent maintenance.

A Balanced Approach to Pool Evaporation
Pool evaporation is a natural process that comes with pool ownership, but with a balanced approach, you can minimize its impact. By using pool covers, optimizing your pool’s water chemistry, and exploring smart solutions, you can enjoy your pool without constantly worrying about water levels. With a little know-how and some eco-friendly strategies, your pool will remain a source of endless summer enjoyment.