What Is A Plunge Pool (Salt Water Option)?


What Is A Plunge Pool?

An inground swimming pool can be a very expensive option to build in your backyard. A total bill between $30,000 and $80,000 isn’t uncommon. Whatever you build, adding a salt water system typically adds $2,000 + to the cost for a decent salt chlorination system.

What if you don’t have the backyard space for a large inground pool or don’t have the money to build one for $30,000 and up? Building a plunge pool might be an option that satisfies your desire for a pool while balancing available space and budget.

A plunge pool is a small, shallow pool typically designed for lounging, wading, or cooling off rather than swimming. It’s often used for relaxation and can be found in gardens, spas, or as a feature in luxury homes. Plunge pools are usually shallower than traditional swimming pools and are designed for soaking and refreshing rather than for exercise or swimming laps.

Let’s go into more detail regarding plunge pools and how they compare to other pool types on the market.

What is a plunge pool?

A plunge pool is smaller than a standard pool in dimensions and water volume and is usually not as deep. It’s an option for homeowners who either have less space to build a pool, a limited budget or who simply don’t want to fill their entire backyard with a full size pool.

A plunge pool may be a great choice for someone who:

  • Doesn’t have a large enough backyard to build a standard inground pool.
  • Wants a pool but wants to retain some backyard space with grass or a garden area.
  • Doesn’t have the budget or simply doesn’t want to spend a larger amount on a bigger pool.
  • Is ok having a pool that may not be deep enough for diving or long enough for swimming laps.
  • Isn’t necessarily concerned with having a pool big enough for pool parties and many swimmers at one time.

As with standard pools, plunge pools do come in various sizes, dimensions, volumes, shapes and styles. Let’s take a closer look at specific options for plunge pools.

How deep is a plunge pool?

A plunge pool is typically 54″ – 60″ or about 4.5′ – 5′ deep but you can have them built 8′ deep like a regular pool if desired. A plunge pool may have an even depth throughout the pool but unless it’s built at least 8′ deep, the pool is not deep enough for diving.

The cost of a plunge pool is considerably lower than an average inground pool as a result given that the ground is only dug around 5′ maximum to accommodate the depth and the overall area to be dug is much smaller in total size than a regular inground pool. Since plunge pools tend to have an even depth throughout, this helps to keep digging costs down, too.

By comparison, the average inground pool is about 5.5′ deep. Commonly in a regular inground pool, the shallow end is smaller in size and is usually around 3.5′ deep whereas the deep end bottoms out at 8′ which is the minimum depth required for a diving board.

A plunge pool is typically smaller and not as deep. This means it's a cheaper install and takes up less space.
A plunge pool is typically smaller and not as deep. This means it’s a cheaper install and takes up less space.

How big is a plunge pool?

A plunge pool is normally around 12′ long and 7′ wide but you can choose many styles such as 8′ x 8′, 8′ x 16′ as well as different shapes such as round or half circle. A plunge pool can therefore be a great option when you don’t have a huge backyard or simply don’t want to use up most of your yard by building a large inground pool.

Rectangular-shaped plunge pools are common given that this shape offers a great deal of usable space to at least enable some swimming distance.

By comparison, an average sized pool is about twice the length as the width so common sizes include 10′ x 20′, 15′ x 30′ and 20′ x 40′ among others.

What can you do in a plunge pool?

A plunge pool isn’t long enough to swim long laps but you can swim short distances in it. It is also suitable for wading, cooling off, water aerobics and just lounging around. An average adult can stand anywhere in the pool and walk around to cool off and depending on the dimensions of the pool, you will typically have enough space for

Due to the lack of depth, diving is not possible since they are typically only 5′ deep on average. Think about your swimming needs and avoid pool buyer’s remorse.

It also depends on what style of plunge pool you get: While you may install a plunge pool that is basically just a mini pool that is long enough for swimming, other plunge pool styles are effectively like a hot tub in design.

What is the design and shape of a plunge pool?

As with standard pools, a rectangular-shaped plunge pool is a common shape due to the maximization of space that if offers. A pool that is roughly twice the length as width enables good use of space in the backyard but also a long enough distance in the pool that you can actually swim laps albeit relatively short ones.

Having said that, you can also choose round plunge pools, semi circles, L-shaped and many other styles.

If you choose a ready made, off the rack fiberglass pool, it can come with your choice of shape, design and size in addition to having various options that you choose such as stairs, seating, lights and more. A custom built pool can of course be even more personal in terms of how you design it.

What material is a plunge pool made of?

As with other inground pools, you can choose between three main kinds of inground plunge pools:

  • Vinyl liner
  • Fiberglass shell
  • Concrete

Vinyl liner plunge pool

A vinyl liner plunge pool is usually the cheapest of the three options. As with other vinyl liner pools, the vinyl will need to be replaced over time and can rip or tear. You can install a salt water chlorinator system with a fiberglass plunge pool just as you can with a standard inground plunge pool.

Note: A metal-walled vinyl liner pool isn’t ideal as metal can be damaged by salt exposure. A polymer (plastic) built wall is a better option than steel or aluminum if you’re choosing a salt system.

Plunge pools usually aren't long enough to do laps and aren't deep enough to dive in. Having said that, you can get splash around and paddle in them and if that's what you need, you're set!
Plunge pools usually aren’t long enough to do laps and aren’t deep enough to dive in. Having said that, you can get splash around and paddle in them and if that’s what you need, you’re set!

Fiberglass shell plunge pools

Fiberglass shell plunge pools are usually in the middle in terms of price. They are prefabricated and after the hole has been dug in your backyard, is lowered into the ground and fastened in place. They come with a wide variety of options such as moulded seats and numerous water returns, lights, and more.

Some pre-made fiberglass plunge pools are designed just like a standard pool but smaller and where the depth is uniform throughout and is good for some actual swimming. But other pre-designed plunge pools are literally just for walking in and sitting in to cool off: Some have moulded steps and seating and essentially make the pool more like a hot tub, just without the hot bubbling water.

Fiberglass pools tend to be very durable and will last. You can install a salt water chlorinator system with a fiberglass plunge pool just as you can with a standard inground plunge pool.

Concrete plunge pools

Concrete plunge pools are the most expensive option for a plunge pool and you will probably want to avoid a salt water chlorination system. Salt is corrosive and can damage the concrete over time. Concrete pools need to be resurfaced as is and exposure to salt will undoubtedly lead to a more frequent resurfacing and possibly serious damage to the concrete.

Some pool builders will strictly advise against a salt water chlorination system and others won’t offer to build one as a result of the potential damage caused by the salt. You’re better off looking at vinyl or fiberglass if you desire a salt water system or think you might want one in the future.

While a salt water chlorination system can be added to a concrete pool, it will come with a price: You will most likely have to resurface the pool more frequently which means emptying the pool of all water, refinishing the surface of the pool and doing any other repairs, refilling the pool and balancing the water. All at your expense.

Can you dive in a plunge pool?

A pool should be at least 8′ deep to be safe for diving. A plunge pool is typically 4′ – 5′ in depth hence the name plunge pool. It’s really only meant for walking into rather than jumping in, certainly if you’re an adult. Plunge pools are good for cooling off in, wading around, and even some swimming back and forth if your chosen design allows for it. But depending on the depth, you are most likely constrained from doing much more than that.

As we’ll see below, some plunge pools are really just hot tubs with pool water that isn’t hot. They are designed with steps and seating and are really only good for sitting and wading in at best.

While you can have a plunge pool dug to a depth of 8′ like a standard pool for a liner or concrete-built one, the deeper you dig the greater the cost. Fiberglass pools are generally ready made and unless you custom design one you will be constrained by what is available in stock in terms of dimensions and depth. Custom designs will increase your pool build cost too.

How much does a plunge pool cost?

Expect to pay between $10,000 – $50,000 for a plunge pool installed, with around $20,000 being the average.

Plunge pools range widely in price just like standard pools due largely to the size, dimensions, depth, options and type of pool you choose.

Custom built pools will cost more and the cheapest overall option you will find is a vinyl liner plunge pool.

Can you have a salt water plunge pool?

You best options for a plunge pool using a salt water chlorination system are a vinyl lined or fiberglass. Salt is a corrosive substance and can damage certain types of materials such as metal and concrete.

A concrete pool is not a good option for a salt water system given the damage salt does over time to the material. Salt can prematurely wear at the concrete and causes pitting over time. A chlorine or bromine concrete pool is a better option.

A salt water system works well and is a very common occurrence with both vinyl liner and fiberglass builds. Since plunge pools tend to be smaller in size, they contain less water. This means you can typically purchase a smaller capacity chlorinator, salt cell and filtration system than you’d otherwise need for a standard pool.

Plunge pool pros and cons summary

Plunge pool prosPlunge pool cons
Takes up less space compared to standard inground pools.Usually not suitable for swimming laps.
Size and depth makes it cheaper than standard inground pools.Typically not as deep as standard pools so diving is usually not an option.
Salt water chlorination is an option for vinyl liner and fiberglass plunge pool designs.Salt water chlorination should generally be avoided for a concrete plunge pool as the corrosiveness of salt damages concrete (and metal) over time.
Offers the option for a nice pool when cost and/or space is an issue.Not as much room to move around so pool parties probably aren’t going to be a thing for you.
Usually requires less cleaning and maintenance given that it’s smaller than a standard pool.You have to be careful with kids who may still try to dive or jump in which can be dangerous if the pool isn’t deep.
Requires less chemicals, a small chlorinator and salt cell, and a small heater and pump, all of which lower your costs.Can be underwhelming to look at especially if you’re selling your house and a potential buyer sees a pool that is smaller then expected.

Carl Mueller

I bought a home with a salt water pool in 2006 and soon realized the benefits over traditional chlorinated pools. On this website I'll discuss all the tips and tricks I've learned over the years. I'll also help you troubleshoot various problems with pools in general and ones specific to salt water pools that I've experienced personally!

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