Can You Use Epsom Salt in a Hot Tub? A Common Question Answered.

25th August 2021

Hot tubs are of course connected with relaxation and relief of muscle pain and tension. Epsom salts are too. It is no wonder then that so many people ask whether the two can be combined. But is it safe to put Epsom salt in a hot tub, or is it going to adversely affect the functioning of the tub? Let’s explore this common question from hot tub users.

Epsom salt in hot tub

Epsom salts help to relax muscle and relieve pain in the neck, shoulders and back as well as the skull. By relaxing the muscles in the skull for example, the magnesium in the salts can potentially ease headaches and migraines. Some research would indicate that magnesium can also reduce inflammation in internal organs, and that Epsom salts are also effective in treating sore feet, muscles, sprains, stiff joints, stress and sunburn.

Many people use Epsom salts in their bathtubs. But if you are asking, can I put Epsom salt in my hot tub, then there are some important considerations to bear in mind.

Chemical reactions

Pure Epsom salts are made up of magnesium sulphate. Being mildly alkaline, this can disrupt the alkalinity and pH balance of your hot tub water. This can lead to reduced performance of the sanitiser, and even corrosion of certain parts such as gaskets, seals and other metal and plastic components.

Dissolved solids

When you use Epsom salts in a regular bathtub, you generally add two cups per bath. Where the average bathtub holds around 80 gallons of water, to reach the same concentration so as to achieve similar therapeutic benefits in a hot tub, bearing in mind the tub holds around 400-500 gallons of water, you would need to add some 10-12 cups of salts. That translates as a huge amount of solids going into your water.

Whereas a bath can be drained quickly and with ease, and the water is only used once, with a hot tub it is not quite so straightforward to replace the water.

Many home spa manufacturers recommend draining and refiling a hot tub when the level of total dissolved solids (TDS) reaches 1500ppm or higher. If this advice is not followed, then the water can turn cloudy. Depending on the individual manufacturer, the warranty may even be voided. If you were to add 10-12 cups of Epsom salts to your hot tub, then the TDS would almost certainly exceed the 1500ppm threshold. This could lead to the tub heating system becoming damaged due to the build-up of scale, and the jets, pumps, water lines and surfaces could also accumulate scale too.

Are there any alternatives to Epsom salts for relaxation and sore muscle treatment?

There are alternative therapeutic products that can be used in place of Epsom salts, and that won’t damage your hot tub.

Look out for specialist hot tub aromatherapy products which offer similar benefits to Epsom salts. Many use magnesium sulphate as the key ingredient, however the main difference is that the products are specially formulated for use in spas and hot tubs and designed to work with just a small concentration. These products will not negatively impact the chemistry of the water, neither will they damage the hot tub.

Epsom salts in hot tub

It is possible to find products that are formulated with moisturising nutrients, natural herbs, botanicals, vitamins and minerals. Combined, these ingredients product a rich aromatherapy experience that will help you de-stress, relax, rejuvenate and experience relief from pain and inflammation. You can also choose blends that help boost energy, induce a better night’s sleep, or improve breathing.

Seeking a relaxing, therapeutic hot tub experience? Look to Hydropool Surrey.

One of the most redeeming benefits of a hot tub is its therapeutic qualities. The range of Serenity hot tubs from Hydropool is designed in conjunction with physiotherapists and osteopaths to provide the perfect balance of massage and hydrotherapy.

Looking to buy a home hot tub? You are welcome to get in touch to find out more about our range of self-cleaning hot tubs, or make an appointment to try one out for yourself at our purpose-built showroom in Addlestone, Surrey.