How Does a Swim Spa Work?

One of the most common questions we hear at Hydropool is: how does a swim spa actually work?

We get it. Although swim spas have been around since the 1990s, most people purchasing are first-time buyers, as more and more people come to them. And it’s difficult to immediately understand being able to swim in a box of water that is ultimately 8 feet wide and as short as 14 feet long.

But you can! Here’s the quick answer:

• a swim spa works by generating a current that provides you with resistance to swim into.
• So the current is always moving around you. You may be supported in place by a tether or by buoyancy jets aimed at your body or you may be a strong enough swimmer to remain in place against the current on your own.
• As a result a swim spa allows you to swim in place the same way a treadmill allows you to run in place.

So the quality of the current is very important when buying a swim spa for swimming. What ultimately makes a swim spa work is its current, its shell shape and how the water returns to the current.

Let’s see if we can make this all make sense. We’ll go through how a swim spa current works and the additional components on a swim spa, so you get a sense of the entire unit.

 

What Are the Main Components of a Swim Spa?

Swim spas may differ in design and features, but most share four essential systems that work together to deliver the swim spa experience:

1. Swim Current System

This is the heart of any swim spa. It creates a current that allows you to swim in place. There are two main types:

• Swim Jets: Water is pushed through multiple jets, creating resistance. The flow is usually adjustable so you can fine-tune your workout or customize it to your swim ability. These can be off the shelf or proprietary. Hydropool, for example, uses patented V-Twin Jets, to create a wide current. If not built well, a jet current can be like swimming into a fire hose. But with proper engineering, swim jets are fully capable of creating a wide, consistent swim area.
• Propeller Systems: These use a fan-like propeller to create a broad, smooth current that mimics natural swimming conditions. While you get a good current, the trade off is that they take up more space in the swim tank than jets do.

2. Pumps and Filtration

Powerful pumps circulate the water, while a filtration system keeps it clean and clear. This ensures consistent flow and hygiene, whether you're swimming or soaking.

As an example, here’s how Hydropool’s system works:

3. Heating System

Swim spas include heaters to keep the water at a comfortable temperature year-round. Whether you want warm water for hydrotherapy or cooler temperatures for vigorous swims, the system gives you control. Swim spas generally come with seating areas, similar to hot tubs, so you can relax and rejuvenate afterwards.

4. Control Panel

Control panels let you adjust swim resistance, temperature, lighting and massage functions, all with just a few button presses.

What’s the Difference Between Swim Jets and Propellers?

Both swim jets and propeller systems are designed to create a continuous current. The main difference lies in how they generate the flow and the experience they provide.

Swim Jet Systems

These systems use high-powered jets to create a stream of water strong enough to swim against.

Pros:

• Adjustable resistance for various fitness levels
• Compact and typically more affordable
• A wide range of options to fit different backyard sizes

Cons:

• The water flow can sometimes feel turbulent or uneven, if steps are not taken to even out the current
• The swim area may be narrower depending on jet placement

In short, there are good jet systems and bad. This is why at Hydropool we always encourage people to try before they buy, so they can appreciate the difference and see for themselves.

Propeller Systems

Propeller-powered spas use a rotating blade to generate a smooth, consistent current.

Pros:

• Wide, even current
• Less turbulence for a natural swimming feel

Cons:

• Higher upfront cost
• Takes up more space due to internal components
• Can be more energy-intensive at high speeds

How Do Swim Spas Create a Consistent Current?

What ultimately makes a swim spa work is its current, which we explained is either made by jets or a propeller.

But a current creates waves. And those waves will crash into the sides of the swim spa. Which will create a messy swim experience unless the swim spa is designed to mitigate against this effect.

Hydropool does this in two ways. With the Aquatic line of swim spas, the shell has “hips” which cause the water to curl around and enter vents which return it to the front of the swim spa to continue creating the current.

This video explains how the Aquatic system works:

With the Executive collection, hips are eliminated on the side of the swim spa. Instead, something called a “current collector” sits at one end. It hoovers up all of the water, before it creates any waves against the side. It essentially creates a conveyor-belt effect of water.

So How Does a Swim Spa Work?

In short: swim spas work by generating a current you can swim against, with adjustable intensity for all skill levels. Shell design also plays a major role in making the swim manageable, so that crashing waves don’t destroy the effect.

Add in heating, filtration, and ergonomic seating, and you’ve got a year-round, all-in-one wellness retreat in your own backyard.

But there’s nothing like trying a swim spa in person. We write dozens of articles to explain, but seeing a swim spa in person clarifies everything. So if you’re interested in this article, we encourage that as a next step.

Visit a showroom to explore your options! Find Your Local Hydropool Retailer.