In the midst the summer season, after a fun day of pool activities with friends and family, you glance at your pool liner only to notice that your pool water level has dropped significantly. Or, perhaps, after a noticeably cool night following a hot day, you notice a difference in water level. This sight would throw any pool owner into a frenzy, questioning if they have a tear in their pool liner or a leak somewhere that has the potential to cost them serious money to repair. However, more often than not, your pool water is just naturally evaporating into the air. In fact, the average pool loses 1 ½ inches of pool water a week through evaporation. So, when you ask yourself, “why is my pool losing water?”, consider these 4 causes of pool water evaporation.
Summertime weather with hot days and cool nights brew the perfect water temperature for not only night swimming, but pool water evaporation. Warm pool water met with brisk cool air creates a mist of water evaporating from your pool. Your pool experiences this every night and it is the main cause of water levels regularly dropping. You can witness this evaporation by turning on pool lights at night; you will notice a thin air of mist above the pool surface, like a steamy blanket over your water. The contrast of summer night and day temperatures is uncontrollable, but purchasing a solar blanket or covering your pool at night will help prevent the water loss that occurs in an uncovered pool.
Lower humidity levels
The air around us acts like a beach towel; when it’s completely soaked with water, it’s unable to absorb any more. If it’s not saturated, then it continues to sop up water when it’s wet. So, like a beach towel, when humidity levels are low, water is more likely to evaporate with less water vapor in the air. High humidity levels prevent evaporation from occurring, so pool owners in humid areas like Florida experience less pool water loss from evaporation. However, pool owners in dry areas like Arizona and Nevada face low humidity and higher rates of evaporation, combated by covering pool water at nightfall.
Look at the location of your pool. Is it out in the sun or under the shade for most of the day? Is it surrounded by any structures, like screens, trees, or bushes, or is it in the middle of a large piece of land completely exposed to the sunlight and elements? You can probably guess that pools exposed to the sun for longer periods of time experience more evaporation than pools that have partial or full coverage from sunlight and other weather elements. Being in the sun for hours upon hours heats up the pool water, lending a hand to the evaporation occurring at night in
cooler temperatures. A shaded pool does not directly face the sun for this amount of time, so it heats up less, thus experiencing less evaporation.
Special features on your pool may be adding to your water evaporation level by keeping your water constantly circulating. Additions like waterfalls and fountains keep water moving, which allows warm water to circulate around the pool and to the surface, evaporating more easily. Similarly, if your pool is used very frequently during the day or night, more warm water can circulate and evaporate into the air. To conserve water circulation and limit evaporation, turn off these special features unless you’re entertaining or using the pool with your family. Limit evening swimming activity to prevent further evaporation as well.
Your pool will naturally lose some water, and that water loss can only be minimized, not eliminated. However, if your pool is losing more than 2 inches a week at a faster pace than normal, then it could be time for professional review of your pool for any leaks or tears in the pool liner. If the water loss is not this severe, then you are likely in the clear; enjoy your pool to the fullest however you like.