When should I drain my pool? Pool industry experts recommend you drain your pool and refill it every five to seven years. No two pools are alike, so there is no set number at which you must drain your pool.
This will vary depending upon several factors including: weather, if the pool is covered or not, bather load, and if it is heated or not. With pools that are covered, a good rule of thumb is that they should not have to be refilled more often than once every 2 weeks.
On average, swimming pools lose about a quarter of an inch of water each day, yet variations in wind intensity, humidity and sunlight can drastically change water loss rates. Some of the strongest and most intense wind in the country can be found in mountainous regions.
An uncovered pool will lose water in the winter to evaporation in the same way it does during the summer. But the water loss is only about a quarter-inch on average during a 24-hour period when the pool is not in use. An uncovered or covered pool can have problems in the plumbing lines or pump.
The pressurized plumbing system pumps water back to the pool after it has passed through the filter. The filtered water returns to the pool through the jet (or return) inlets. The plumbing that returns the water from the filter to the pool is often referred to as return plumbing.
RECOMMENDATIONS TO MINIMIZE WATER LOSS
The number-one way to combat evaporation is with a pool cover. It's estimated that a pool cover will reduce evaporation by 95 percent. Solar covers can heat your pool in the off-season, too. A pool cover reduces the pool's chemical consumption and reduces your cleaning time.
Pool Is Losing 1 Inch of Water Per Day
Losing more than ½” of pool water per day indicates you likely have a leak in your pool's structure or your pool pump system. You should call your pool service for a thorough leak inspection. You might not be able to keep up with refilling your pool at this point.
The average pool water evaporation rate is about a quarter of an inch of water per day or more than two inches in a week, which on a 33′ x 18′ swimming pool (an average pool size) is more than 2500 liters or approximately 600 gallons a week; this may vary depending on your climate and the factors listed above.
You can do the “bucket test” on your pool to measure evaporation. Place a bucket of water beside the pool and mark both the water in the bucket and the pool water level. Wait 24 hours then check the loss of both. If the pool loses more water than the bucket, then you have a leak.
Lower Your Water Temperature
As we know, warmer water evaporates at a faster rate than cooler water because the molecules are moving faster. As the temperatures drop, the warm water evaporates even faster.
If your pool lost water overnight and it is more than the quarter-inch due to evaporation, you probably have a leak. Evaporation accounts for a minor amount of water lost each day. Losing a half-inch or more overnight indicates a problem.
The differential that occurs between the pool water temperature and the air temperature on late summer nights causes water to evaporate at an accelerated rate. In some cases you might see a water level difference of 1-3 inches overnight. Depending on the size of your pool, that can be over 500 gallons of water loss!
The average swimming pool takes 18,000-20,000 gallons of water to fill.
Most pools experience between 3mm - 7mm of water loss each day, depending on where you live.
The level at which pool skimmers function properly is between one third and about half way up the opening of the pool skimmer. If the water level is too high the debris floating next to the opening may pass by without being pulled into the skimmer.
Natural causes such as wind, heat and humidity can contribute to pool water loss. This is a big deal, because if your water level gets too low it may cause your pool pump to suck air and run dry, which can damage it.
How Quickly Does It Evaporate? For evaporation, anywhere between 2 millimeters to 2 inches per week is about what you should expect in terms of pool water loss.
The average pool will lose anywhere from 1/4″ to 1″ per week, and you could lose up to 2,000 gallons a month in the summer.
What happens if your swimming pool water level is too low? If the water in your swimming pool is too low, the skimmer can bottom out and suck air into your filter system. And when that happens, you're at risk for burning out the motor on your pool pump.
Typically, pools lose water for one of two reasons: Evaporation or a leak. Evaporation naturally occurs in any body of water, but it may increase under certain conditions, such as hot, humid weather. Leaks, however, indicate a bigger problem that a professional may need to address.
Heated pools do result in more evaporation, so more make-up water is required to refill heated pools than unheated pools. Whether using solar heating, heat pumps, or gas heaters, heated pools do require more water.
Pool Losing Water After Heavy Rain
Due to a heavy rainstorm, water loss is more common with vinyl liner pools that can be damaged, come loose, or float to the top. With other types of inground pools, it is vital to get the water level down. If not drained, the water balance will change, causing cloudy water and more.