You are not alone if the first electric bill after installing your pool nearly gave you a heart attack. Many homeowners are shocked at the increased electrical usage. If you want to lower your electric bill, then you need to know how long you can leave your pool pump off.
You can leave your pool pump off for 24 to 48 hours with minimal danger that you will upset the balance of chemicals and additives required to keep the water clean and safe. However, if the pump is left off for an extended time, it can take up to 5 days to clean it.
Whether you are trying to cut back on your electric bill or leaving town for a week, you should know how a pool pump works to keep the water in your pool clean and safe.
What Happens When You Leave a Pool Pump Off Too Long
To understand what will happen if you leave your pool pump off, you need to know what a pool pump does. A common misconception is that pool pumps exist to suck dirt out of the water. While it is true that a pump can draw out dirt, leaves, and other organic material, that is not its only purpose.
Instead, the pump’s primary purpose is to circulate the chemicals that prevent the growth of algae and harmful bacteria. Without the pump, the bromine, chlorine, algaecides, and pH balancers that you put into the water won’t circulate properly.
Can You Circulate Pool Chemicals if the Pump Is Off?
You can circulate pool chemicals if your pump is off, but most methods have drawbacks. Suction-side or pressure-side pool cleaners won’t work unless the pump is operating. Robotic pool cleaners are automatic cleaners that work independently of your pool’s pump, but they are expensive.
Plus, you must keep their batteries charged.
You have several other options to circulate the water (which will be discussed in a section about caring for your pool if you lose power).
However, it’s unlikely that you will be able to circulate the chemicals enough on your own to avoid dead areas. Most pools have areas with poor circulation that need to be cleaned frequently, and once you clean those areas, the organic material must find its way to the filter area to be eliminated.
Using a Pool Shock as a Back-Up
If your pump breaks just as your trip is about to start or you are adamant that you don't want to run the pump while you won't be able to enjoy it, at minimum, you should shock your pool. It will help if you have 10-12 hours of sunshine and use a solar cover to keep the water hot.
Your pool won’t be damaged if you don’t run the pump, but you will need to "ungreen" the water upon your return. This process can take up to five days. You will need to:
- Remove large debris.
- Adjust pH and alkalinity levels to a level where the water will be clear.
- Shock the water again.
- Filter and backwash repeatedly.
Once they learn how long the process of getting clean and clear takes, many people decide to pay to have the pump run.
Determining How Long You Can Leave the Pump Off
How long you leave the pump off is determined by several factors:
- The turnover rate
All three of them need to be considered when coming up with an answer.
The Turnover Rate
All the water in your pool needs to run through the filtration system. That is why running the pool for an hour or two is not adequate—unless you have a tiny pool. The turnover rate is how many hours are required for all the water in the pool to circulate through the system.
To calculate the turnover rate, you need to know how much water your pool holds and the amount that your pump circulates per hour. Some localities have specific guidelines, such as all the water needs to be turned over every six hours. The professionals who installed your pool would have informed you of specific requirements.
You can find online calculators to determine how much water your pool holds, such as this pool volume calculator. Obviously, figuring out how much water a rectangular pool holds is easier than a round one. It’s also easier to determine how much water a pool holds if the base is level.
Most homeowners ignore the calculations, which can get complicated quickly, and use a ballpark figure. That figure is usually in the 6-to-8-hour range. People who prefer to run their pumps at night to take advantage of reduced electricity rates run them for 8 hours to offset the 16 hours of debris build-up.
Others split the pump times between morning and night.
The pool pump is designed to circulate the chemicals you add, but it also needs to remove debris. People often associate debris with leaves and insects, but fine matter such as dust, pollen, and sand also need to be removed.
And let’s not forget the bather load—the sweat, dead skin, cosmetics, and suntan lotions of the swimmers.
This is the third factor to consider when determining how long you can leave a water pump off. Higher temperatures and more sunlight mean longer run times. And don’t think that you won’t need to run your pump when temperatures reach freezing—unless you plan to winterize your pool.
How To Care for a Pool When the Pump Is Off
If your pool's circulation system is put out of commission due to a pump malfunction, power outages, or major storms, don't panic—you can keep the pool water clean with a few easy steps.
To care for you pool when the pump is off:
- Clean the water before adding sanitizers. Debris can quickly use up the sanitizer, which will require that you use even more. Pool nets or battery-powered pool vacuums can help with that. I recommend the Pool Blaster Leaf Vac since it’s lightweight and has an extra-large bag.
- Sanitize the water using fast-dissolving chlorine. Since most chlorine tablets are designed to dissolve slowly, double-check that you use the tablets that dissolve quickly. If you live in an area prone to storms, it might be best to have some on hand in case of extended power outages.
- Add algaecide to prevent algae blooms. This will be necessary if the pump stops working in the summer. Also, look for non-metallic, non-staining controls. The API Store Algaefix is a great choice because it doesn’t contain copper.
- Circulate the water. If you have been using a battery-powered cleaner, you’re in luck. Most leaf baggers can be run on the water current of a hose (although this will raise the water level of your pool).
If none of those options will work, you could use your pool brush to agitate the water. While you’re doing so, you can also clean the sides of the pool to prevent algae and staining.
Reasons To Leave Your Pool Pump Off
People who want to leave their pool pump off usually fall into two categories—those who will be away from home and those who need to cut back on their electric bills.
No matter which category you fall into, you likely want to save on the electric bill.
If you won’t be home for a week, why do you need to run the pump? No one will be using the pool, and depending on where you live, skimming leaves and dirt out of the water won’t be a big deal.
Or, if you live in an area that doesn’t have ideal pool weather year-round, it makes sense you might be tempted to leave the pump off.
But in any case, there’s the sticker shock associated with a pool—not the price of the pool, but the increased electric bill—that often surprises new pool owners.
Continue Pool Maintenance During Winter
Although you won’t have to spend as much money in the winter, you should still do some maintenance. Even though algae rarely grows on the water in the winter, it is common to have some appear in the maintenance system, along with debris.
Additionally, to protect your pool’s components from freezing, run the heater and filters occasionally.
If you use a cover in the winter, running the pump for an hour will circulate the warmer surface water with the colder water on the bottom of the pool.
Pool owners use different strategies for how often and when they run their pumps. Some owners calculate precisely how much water is in the pool, and others use a rule of thumb. If you want to limit how long you run your pump, break up usage into several hours in the morning and several in the evening.
However, the longer your pump doesn’t run, the greater the likelihood that algae and bacteria will take over your pool, making it unsafe for swimming.