Smaller than a pool but bigger than a hot tub, swim spas are the in-between option that lets you relax and work out at home—and they come with their own unique maintenance needs.
If you have experience with water care for either pools or spas, you will already be familiar with a lot of the requirements when it comes to swim spas. But there are also several key differences you need to know about.
So, let's take a look at what's needed to maintain a swim spa.
What chemicals should you put in a swim spa?
The basic principles of water chemistry for swim spas are actually the same as for regular spas or hot tubs: sanitize with chlorine or bromine, clean the filter regularly, and keep the pH, total alkalinity and calcium hardness balanced.
Swim spas are generally cooler than hot tubs, which means granular chlorine is usually the better sanitizer choice. However, you can still opt for bromine instead if you're overly sensitive to chlorine.
Test daily (or every few days if you don't use your swim spa regularly) with test strips, and adjust the levels as needed:
- Add sanitizer (you also need to shock the water weekly, or after every use):
- Maintain a healthy water balance:
- pH between 7.2 and 7.8
- Total alkalinity between 80 and 140
- Calcium hardness between 150 and 250
You can use the same chemicals as you would use in any pool or spa; you'll just need to calculate the amounts based on the capacity of your swim spa.
The volume of water in a swim spa is around 1500 to 2500 gallons, depending on the model.
If you're looking for a way to reduce chemical usage, consider buying a swim spa with an ozonator. These are usually optional extras added at the factory.
They work by releasing ozone into the water, which helps to oxidize contaminants. This reduces the work of your sanitizer, which means you can often get away with adding lower quantities of it.
How often do you drain a swim spa?
Generally, the larger the volume of water, the less frequently it needs to be changed. The good news is that you should only need to change the water in a swim spa every 6 months.
You may even be able to leave it longer than this, especially if you don't use your swim spa frequently.
How do you know when it's time to change the water?
It essentially comes down to the total dissolved solids measurement.
Total dissolved solids (or TDS) is a measurement of everything that has dissolved in your swim spa water. This includes minerals, chemicals, or contaminants from bathers.
If you don't have a way to measure TDS, you can also take a water sample into a local pool and spa dealer who should be able to test it for you.
However, you can also tell that it's likely getting too high if you start to notice any of these signs:
- Colored, cloudy or dull water
- Difficulty maintaining the water balance
- Algae growth despite adequate sanitizer
- Eye and skin irritation
Did you know? Swim spas are actually easier to maintain than hot tubs. The cooler water means they require fewer chemicals, the levels are more stable, and the water needs changing less frequently.
If you don't want to do a full drain-and-refill, a faster option is to partially drain and just replace some of the water, which can still help to bring your TDS down to a more manageable level.
What is the ideal temperature for a swim spa?
If you plan to use your swim spa for exercise, the ideal temperature range is 80-90°F. Aim for the lower end of this range if you live in a warm climate, or the upper end if you're using your swim spa for workouts in a cold winter.
However, manufacturers estimate that more than half of swim spa customers are not particularly interested in using their swim spas for exercise.
Most swim spas can therefore also be heated to standard hot tub temperatures, which are typically around 100-104°F.
Dual zone swim spas
While some swim spas are a single body of water, a bit like a large hot tub, many manufacturers now make 'dual zone' models.
Dual zone swim spas have a split design, with two separate areas partitioned by a wall: one designed for sitting and relaxing, and the other for exercise.
In a dual zone swim spa, each section has its own heater, controls and equipment, which means you can set the relaxation side to be warm like a regular hot tub, and have the other side cooler so it's set up for workouts when you'll want to avoid getting too hot.
How long does it take to heat a swim spa?
Swim spas can take 20-40 hours to heat from cold. The exact time will depend on the ambient temperature and location of the unit, the size of the swim spa, how powerful the heater is in your particular model, and the starting temperature of the water.
How much does it cost to maintain a swim spa?
Multiple factors contribute to the cost of running a swim spa:
- Necessary chemicals and related parts like filters can cost around $15-$35 per month, spread over the cost of a year.
- Energy costs will vary depending on your local climate, but you can expect to pay $50-$100 per month to power a swim spa. This makes them much cheaper to run than a pool, particularly if you have cold winters.
- Repair costs are hardest to predict; some years you may spend nothing, and other years a replacement part could cost several hundred dollars. It's a good idea to budget an extra $100-$150 per month for repairs, even though you may not end up spending it most years.
One of the best ways to keep swim spa maintenance costs down is to invest in a quality model from a reputable brand in the first place.
Avoid manufacturers that use proprietary parts wherever possible, look for eco-friendly features like quality insulation, and choose dealers that offer strong warranties and have a good reputation for after-sales service.
How long will a swim spa last?
A quality swim spa should last up to 20 years.
To prolong the life of a swim spa, maintaining a healthy water balance is one of the best things you can do. If pH levels are incorrect, over time the water can become corrosive to your spa's mechanical parts. Or hard water can cause scale buildup. Both these things can lead to more wear and tear than necessary.
Perform regular inspections of your swim spa's shell and cabinet too. Get any signs of scrapes or cracks treated before they can turn into leaks, which could cause rotting and damp issues in the insulation or components.
When kept in good condition, a quality swim spa can serve your fitness and relaxation needs for decades.