Yes, a pool can lose water without leaking. It’s often due to factors like evaporation, splash-out, backwashing, and regular use.
But the more important question is whether the amount of water loss makes sense. A small drop during a hot, windy week may be normal, while something like a steady drop after every refill, especially when the pool is not being used much, is worth checking.
In this post, we’ll look at why pools naturally lose water and how to tell when that loss may point to a bigger issue.
Not every drop in water level means something is broken. Pools are exposed to weather, movement, and regular maintenance, so some water loss is a normal part of pool ownership.
Here are some of the most common non-leak causes of a pool losing water.
Evaporation is one of the top reasons a pool loses water. This usually happens faster during hot, dry, or windy weather. In typical summer conditions, a pool may lose about 1/4 inch of water per day, though humidity, wind, and temperature can change that. The sun warms the water, dry air pulls moisture from the surface, and wind helps carry that moisture away.
So if your pool level drops a bit during a stretch of summer heat, it could very well be due to simple evaporation.
Splash-out is exactly what it sounds like: water leaving the pool during normal use.
Kids jumping in, people climbing in and out, pool games, and general swimming can all send water onto the deck. You may not notice it happening because the water spreads out or drains away, but after a busy day, the pool level can look lower than it did that morning.
If your pool has a sand or DE filter, backwashing could easily be the culprit of a lower water level.
See, during backwashing, water moves through the filter and out through the waste line to clear out debris. So after a longer backwash — or after backwashing more often due to storms, heavy use, or dirty water — the lower water level may be tied to maintenance rather than the pool itself.
You may be surprised by how small water losses can add up when the pool sees heavy use.
This can include:
On their own, these may not seem like much. But during peak swimming season, these small changes can make the water level harder to judge from one day to the next.
There’s no perfect number that applies to every pool. Water loss depends on a mix of factors, including the weather, pool size, sun exposure, wind, temperature, and how often the pool gets used.
A small drop over a few days can make sense during hot or windy weather. But if the pool is losing water quickly, dropping even when it is not being used, or falling again soon after you refill it, it’s worth paying closer attention.
A leak or equipment issue may be more likely if you notice:
If you suspect something is up, track the water level for a few days, along with the weather, pool use, and any maintenance, to get a clearer picture of what’s actually happening.
You can use whatever method you’d like, though a simple bucket test can help tell whether the drop is normal evaporation or a possible leak: fill a bucket with pool water, set it on a pool step, mark the water level inside the bucket and on the pool outside it, then compare the two after 24 hours with the pump off.
If the water keeps dropping and the reason isn’t clear, guessing can get frustrating. It can also lead to bigger problems if the pump starts pulling in air or an equipment issue gets missed.
So, whether your pool is losing water faster than expected, the level keeps dropping after refilling, or you cannot figure out the cause, Clark Pools and Spas can help. Our team can inspect the pool and equipment, look for signs of trouble, and help you understand what is going on.
Contact us to book a pool service appointment today.
