An automatic pool cover is electrically operated and is put in the closed position when you are not using the pool. It will keep debris like leaves and twigs out of the water while also providing some level of security so that a child or small pet cannot fall in although specific models have varying weight limits.
The question is: Can an automatic pool cover be used with a salt water pool given that metal parts may become rusted due to the corrosiveness of salt water?
Salt water is corrosive and can damage metal parts among other parts of your pool. Depending on the model and brand, some automated pool covers might be better suited to resist salt water than others so it’s best to check before purchasing.
Is an automatic pool cover compatible with a salt water pool?
Salt water – and exposure to water in general – can corrode metals like stainless steel and aluminum. Both materials are often used in the manufacture of automatic pool cover systems.
There have been reports of aluminum pool fences deteriorating over time due to corrosion from salt water from the pool collecting at the base of the fence poles. And fences are typically built several feet away from the pool. Automatic pool covers are built directly at one end of the pool itself where splashing may occur regularly.
While the actual cover is probably made from a strong vinyl, an automatic pool cover system may have numerous metal parts including:
- The motor which will typically have a stainless steel shaft and gears.
- Stainless steel brackets.
- The track that the cover wheels turn on as the cover is deploying along with the recessed guide to keep the cover inline.
- The lid of the cover which may be made from aluminum.
- The metal screws and nuts as well as end brackets holding the cover in place on the roller.
- Sliders and pulleys to move the cover over the surface of the pool.
- Coping (finishing) which may be made from aluminum.
Some models of pool cover may additionally have chain-driven mechanisms which can also corrode.
How susceptible is your automatic pool cover to salt water?
What happens when these metals parts gets wet with salt water, dry, get wet again with salt water, etc? Is your chosen brand and model high enough quality and designed well enough to withstand the corrosive effects of salt water exposure over time?
Splashing in the pool alone can saturate many parts of the pool equipment and since the cover is built to sit on top of the water surface, it’s close enough to get wet regularly.
Even though a salt water pool has a salt content of 2700 ppm – 3400 ppm which is much lower than that found in the ocean – which is around 35,000 ppm – the fact is that it is still salt water which is known to be very corrosive.
Even a metal pool ladder can rust which can leech small amounts of metal into your pool water which can additionally lead to stains on your pool liner.
Keep that in mind if you are considering an automatic pool cover for your salt water pool. Product quality, design and water resistance are important.
What’s the difference between a solar pool cover and an automated pool cover?
A solar cover or solar blanket is that blue bubbly cover you probably remember seeing at a friend’s pool when you were younger. These days you can get them in many different colors but dark blue like ocean water was the go-to shade back in the day.
A solar pool cover keeps existing heat in the pool while also helping the sun’s rays penetrate the water and heat the pool water even more as the day goes on and the sun gets higher up in the sky and thus more powerful. You place the cover bubble side down on the surface of the water since the bubbles help to trap heat and transfer it to the water.
A solar blanket is great when you want to retain heat in your pool overnight while also getting advantages from reduced water evaporation and perhaps helping to keep debris like leaves and small rodents from falling in and drowning. If you have a small(er) budget, it’s much cheaper than other options like an automated cover.
It can also easily be cut to the size and shape of your salt water pool.
As we’re seeing on this page, an automated pool cover on the other hand is mechanical, sturdier, automated (clearly), operated by electricity and much, much more expensive to buy and replace. It might need servicing or repairs from time to time, too.
How much weight can an automatic pool cover hold?
The weight limit of an automated pool cover depends on the brand and model. Some are advertised as having a limit of up to 2,000 lbs. Others are not nearly as sturdy.
Some specifically say in the sales literature that it can help keep small pets and kids from falling in which indicates that they’re not necessarily saying a heavy adult could be supported.
Some manufacturers are loathe to actually answer the question specifically (I asked several of them) because they don’t want you walking on them or thinking you can accidentally fall on them and not cause damage. The responses I received regarding weight limits generally pointed me in the direction of the ASTM International (formerly known as American Society for Testing and Materials) standards which we’ll touch on below, but without actually mentioning an actual maximum weight.
What about winter snow and ice though?
If you live in an area that gets significant snowfall and you plan on using your automated pool cover during the winter months, you want to first ensure your chosen model can support snow and ice especially when it starts to melt. Large ice blocks can develop on specific parts of the cover which can centralize the weight.
How safe are automatic pool covers?
Depending on the model, many electric pool covers can hold a significant amount of weight and this can be an advantage if you have kids or pets. But pool covers come in various shapes, designs and sizes so you have to be careful that you don’t rely on one for something that it can’t provide.
Certainly, a high end winter pool cover can often hold significant weight while also keeping debris out of the water over the winter months when the pool is closed.
As mentioned above, a pool cover’s weight limit should be carefully confirmed prior to purchase and take into consideration what you need it to withstand. Heavy snow and ice in the winter is one consideration.
Either way, a pool cover of this kind is not meant to be walked or jumped upon and is not for playing on either.
Check the ASTM International standards document for pool covers which you can learn more about by clicking here. This is the standard that pool cover manufacturers follow when they want to adhere to the strict requirements and label their products as meeting these standards.
What are the major benefits of an automated pool cover?
One major manufacturer of automatic pool covers suggests reductions of 90% in evaporated water, 70% in heating costs, 50% reduction in electricity costs and 70% in chemical usage can be achieved.
Do these numbers seem reasonable?
Remember: Salt water pools generally use less chemicals than regularly chlorinated pools but there could be some additional savings to be had. So the other three claims are worth looking at too.
Let’s take a closer look at each statement.
- 90% reduction in water evaporation – This is probably a fair point. It has been proven that solar blankets significantly reduce water evaporation by protecting the water from the direct rays of the sun while allowing heat in to warm the pool water. It’s possible a well-used and quality automatic pool cover could do the same.
- 70% reduction in pool heating costs – Again, a quality automatic pool cover can help to retain the warmth of the pool water and attract the sun which can reduce the need to heat your pool with a gas or electric heater. By keeping the cover on overnight when the temperature drops, you also can help to retain heat. In the morning the pool temperature won’t have dropped as much as it would otherwise, had the pool been left uncovered.
- 50% reduction in electricity costs – With an automated pool cover in place, it’s likely you might need less pump run time as the water may require less filtering since the cover won’t let debris in. Less debris can mean less chlorine is required and on top of that, you don’t have to run the pump as much to operate the salt chlorinator. So a reduction in electricity usage could be achieved but perhaps not as high as 50%.
- 70% reduction in chemical use – Salt water pools already tend to use fewer chemicals so this 70% number is probably very high. Much of this number I suspect will be from reduced chlorine usage as the cover will protect the chlorine in the water from the sun’s damaging rays. The cover can also protect from leaves, twigs, etc from falling into the water which also eats up chlorine. But for a salt water pool owner, having a salt chlorinator system alone reduces chemical usage, especially chemical chlorine which you don’t use regularly as it is.
An automatic pool cover at a minimum should help to provide a safety component, help to keep the pool clean and keep the water temperature up at night so in that regard, reduced chemical usage and heating costs could certainly be achieved.
Final thoughts
Something to consider regarding an automated pool cover: A solar blanket just sits on top of the water loosely and is neither airtight nor secure. So air can get in easily and chlorine gases if any can escape. It’s still not recommended to leave a solar blanket on a pool for more than a day or so as it can promote algae growth.
An automated pool cover on the other hand covers the entire pool and while not airtight, certainly limits airflow. Some manufacturers recommend ensuring you don’t leave their cover in the closed position for more than a day in order to allow chlorine gases to escape. Some specifically mention to open the cover on a daily basis in this regard.
Plus, the more you leave a pool covered in the middle of a hot summer, the more likely algae can begin to develop.
Summary
An automated pool cover can be a good albeit expensive choice to protect your pool overnight and perhaps over winter. It can keep heat in, debris out, and may provide a safety component too should your chosen model have a high enough weight limit.
How much does an automatic pool cover cost? We’ve written about that too. This article also contains much more information on the topic of automatic pool covers including costs compared to other options, pros and cons as well as lifespan.
When choosing one, check with the manufacturer regarding the suitability for their product with a salt water pool system. Salt water is very corrosive and you don’t want the cover’s metal parts to get damaged as a result of exposure.