How Often Should I Drain My Pool?

So you’ve just filled up your pool and are ready to open it up for leisure. Except that the water sitting for a whole day is making you nervous. You know that much water isn’t supposed to perpetually sit, inviting bacteria and other problems. Should you drain it in a few days?

You should drain your above ground pool every six months and your inground pool every two years. This frequency may change based on how well or how poorly you maintain your pool and protect it against algae build-up, microbial growth, chemical imbalance, and hydrostatic pressure.

In this article, you will discover what happens when a swimming pool isn’t drained on time, what you can do to avoid having to drain your pool regularly, and why inground and above ground pools have different frequencies of pool draining.

What Happens if I Don’t Drain My Pool?

Draining your pool can be very hectic, especially if said pool holds a significant volume. It can also cost a lot, and most people try their best to maintain chemical balance and water health levels just to avoid having to drain their pools more frequently. Knowing what dangers a perpetually full pool is prone to can help you decide whether you should empty your pool or use other fixes for a given timeframe.

Your Filter Pump May Get Frozen or Burned

Depending on the weather, when your pool’s not in use, the water around your pool’s filter pump may freeze or boil the pump. During winters, pools are usually shut down. It is advisable to partially drain the pool and apply antifreeze to pumps and plumbing so that nothing gets frozen and damaged. 

If you live in a sunny environment, you may not have to worry about winters, but July heat is a menace to your pool’s plumbing just as much as an Alaskan winter. Moreover, you don’t even have an anti-free type solution to prevent your pool water from damaging its fragile parts. Fortunately, you can move an above ground pool or temperature-regulate a semi-drained inground pool while securing it further with formidable shade.

The Pool Frame May Crack

Still, water produces hydrostatic pressure while freezing water expands and causes ice damage to the frames of your pool. Inground pools can withstand more hydrostatic pressure than the ones above ground, but neither variety is perpetually immune to this pressure. If anything, inground pools cause significantly higher loss when affected by hydrostatic pressure as they pop out of the land they’re embedded in. 

An above ground pool simply buckles and collapses, something that can be reversed at a lower cost. Draining your above ground pool and partially draining your inground pool can be a reasonable solution. Larger pools deploy wavemakers to decrease the required frequency of drainage.

Bacterial Infestation

While both frigid and sweltering temperatures are detrimental to the physical body of your pool, lukewarm weather conditions are harmful to its content. Sure, your pool frame may not get cracked if you’re in a region with mild weather, but your pool water will have the perfect temperature to promote microbes to propagate. 

At the height of malaria-related deaths, water bodies were seen as the ultimate risk. The US has come quite far since, and still water isn’t as deadly, but that doesn’t mean it is safe. If your pool water isn’t drained, its chemical composition will eventually get lopsided. One possible result of this is skin irritation.

Fungal Growth

This effect is similar in its end result to bacterial infection except with a visible impact. Fungal growth in stagnant water is visible once the colony of fungi propagates enough. Depending on your disgust sensitivity, this can be considered better or worse than bacterial growth. The cause and effects in the broader sense are the same: pool users are at risk when using the pool. If the fungal growth is visible, there’s the added drawback of lack of desire to use the pool again.

Why Pool Draining Is Different For Inground and Above Ground Pools

You may have noticed that the frequency with which you’re supposed to drain an above ground pool is usually different from how often your local fitness club is required to drain its pool. You may be wondering why that’s the case. Several factors contribute to this difference.

Water Volume

You must drain your above ground pool more often than an average inground pool for the same reason as you have to drain a bathtub more often than a jacuzzi. The smaller a volume of still water, the higher the risks of microbial infestation. 

It isn’t that one body of water becomes less likely to attract bacteria or fungus; it is just that the density of these microbes becomes much larger right away in a relatively smaller volume of water. Since inground pools are usually larger and contain a higher volume of water, they can afford to get a few bacteria without becoming an immediate health hazard.


One of the reasons you should drain your above ground pool more often is simply because you can. It is always healthier to err on the side of draining more often than you should. It is just too costly to do that with an Olympic-sized pool. 

That’s why such pools use other solutions covered in the next factor. Draining a bigger pool has greater environmental and monetary costs. Since an above ground pool doesn’t cost as much, depending on size, it is advisable to drain them more often.

Maintenance Technology

Larger swimming pools are too expensive to drain but are also a liability if left alone. That’s why homeowners with such pools rely on expensive technology to protect their respective pools from adverse effects of hydrostatic pressure, microbial infestation, and extreme temperatures. Fortunately, these solutions are no longer as expensive as they used to be, and even above ground pools can use them to balance the chemical composition of their pool water.

How to Maintain Water Health Without Draining Water

Regardless of which type of pool you have, you’re not draining the water every day. In fact, you should not drain the water as often because cheaper and more environment-friendly solutions to safeguard your water and pool exist. You just have to ensure the water’s pH is balanced without replacing it and make sure there’s enough circulation to keep the contents filtered. Here are some products that can help with this.

440 Chlorine Dispenser

If you’ve read my post about pool chemicals, you know what order to put them into your pool alongside the benefits of each chemical. Using a chlorine dispenser takes much of this stress off your mind as it automates the chlorine dispensing task. 

Powered by chlorine tablets as opposed to chlorine powder, this system ensures the longevity of the chemical by distributing it in a spaced-out manner while retaining the tablet. Chlorine powder, on the other hand, gets diminished much quicker once dissolved thanks to its relatively rapid interaction with sunlight.

Clorox Chlorine Stabilizer

If you want to keep your pool stain-free but don’t want to use tablets, you can extend your chlorine powder’s effectiveness post dissolving by using it alongside a chlorine stabilizer. By reducing the sun’s impact on chlorine, the Clorox chlorine stabilizer helps chlorine last longer in your swimming pool. 

Consequently, you don’t have to drain your pool as often. An untested pool left with low chlorine content can soon have undesirable build-up, which brings us to our next recommended product.

Dolphin Escape Robotic Pool Cleaner

Many times, draining the pool is a purely aesthetic decision because certain stains need to be scrubbed, and it is more convenient to clean the pool walls and ground when the pool isn’t filled to the brim. Fortunately, this robotic cleaner takes the task off your hands and executes it without the need to drain your pool. You can simply turn it on and place it inside the pool, allowing it to work its magic even when you and your friends are in the pool.

Clorox Brominating Tablets

You can use brominating tablets to kill algae before they become a visible menace. Generally, bromine is a chlorinate alternative, but it is also used alongside chlorine in some instances, albeit with a high-functioning pH stabilizer. 

You can load up your brominating tablets in a chlorine dispenser and have the same effect. Roughly speaking, brominating tablets are like chlorine tablets but for warmer pools. If your pool receives a lot of sunlight, you may want to opt for bromine as the alternative. Regardless of whether you use bromine or chlorine, you still get to defer your pool draining by sanitizing its water content regularly.

Final Thoughts

Draining your swimming pool relieves the pool’s frame of water stress and gives you the opportunity to refresh the pool’s contents instead of letting it sit and become a chemical soup with a side of algae. It is a healthy exercise that, if done too often, can have environmental and monetary costs. That’s why it is done sparingly, and other products are used to lower the need to do it often.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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