Hot tubs are famous for relaxation and relieving sore muscles and joints, while Epsom salts are thought to provide healing properties. Most people submerge their bodies in hot tubs or soak various parts in Epsom salts to find relief.
Thus, some may wonder and ask, “Can you put Epsom salt in hot tubs?“, hoping to combine their effects. That is especially since Epsom salts can easily dissolve in water and are safe, affordable, and easy to use.
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What Is Epsom Salt?
Epsom salt was first refined in the rushing waters of a saline spring in Surrey County, England, near a town with the same name.
Although it looks almost similar to regular table salt, its chemical composition differs.
Epsom salt is magnesium sulfate, while the latter is sodium chloride.
Can You Put Epsom Salt in Hot Tubs?
The answer is it depends. You can put it in a wood-fired hot tub but not an electrically-operated one.
As mentioned, the salt has magnesium sulfate, an alkaline compound, which can disturb the hot tub water’s pH level and total alkalinity.
These changes can cause other problems. It may corrode electric hot tub parts.
The unbalanced water may also cause poor sanitizer performance.
Also, the salt increases the water’s TDS or total dissolved solids that you can’t easily drain from the hot tub.
Most manufacturers require hot tub owners to drain and clean the tub before refilling once it reaches 1500 ppm and higher of total dissolved solids.
Failure to follow this maintenance step will void your warranty.
A high TDS level also results in cloudy water and possible scale build-up.
The spa heaters suffer the most when there is scale build-up. Other parts also risk getting damaged if you cannot maintain the correct water balance.
Not only that, but Epsom salt can also corrode the plumbing, leading to flash burns for the users while soaking.
With that in mind, you can always put Epsom salts in your regular bathtub.
What Are the Best Alternatives to Epsom Salt for Hot Tubs?
Since the answer to “Can you put Epsom salt in hot tubs?” is a no if you have an electric unit, what can you use instead?
Try using the following alternative products that offer similar benefits as Epsom salts:
Hot Tub-Safe Mineral Soaks
- Description: Specially formulated products designed for spa use. They often contain magnesium, potassium, or other minerals, but without sulfates that can damage equipment.
- Benefits: Soothes sore muscles, reduces stress, and is compatible with hot tub systems.
We recommend using Medicine Springs Skin Formula.
Medicine Springs Mineral Salts bring the healing power of natural hot springs right to your bathtub or hot tub. Designed with a skin-focused formula, these mineral-rich salts feature Dead Sea and hot springs ingredients that promote relaxation, joint relief, and skin rejuvenation.
Safe for tubs, plumbing, and filters, they dissolve easily and offer a spa-quality soak for up to 400 gallons of water in hot tubs or 100 gallons in baths. With ingredients like magnesium and calcium, this mineral soak transforms your bath into a luxurious, therapeutic escape.
Aromatherapy Spa Crystals or Liquids
- Description: Made for hot tubs, these products contain essential oils and skin-softening agents in a non-damaging formula.
- Benefits: Adds fragrance and relaxation effects without affecting water chemistry or causing build-up.
- Look for: “Spa safe,” “Hot tub compatible,” or “Non-foaming” on the label.
We recommend using Spazazz Destinations – Hawaii – Aloha Paradise – Natural Spa & Bath Salt Aromatherapy Crystals.
Transport your senses to the islands with Spazazz Destinations – Hawaii Aloha Paradise spa and bath crystals. This 22oz jar blends warm citrus and amber scents with skin-softening minerals like magnesium and aloe for a luxurious, island-inspired soak.
Safe for hot tubs, kids, and spa systems, it’s oil-free and won’t clog filters or alter water chemistry. Just add 1oz per 100 gallons for a relaxing tropical escape. Proudly made in the USA by a woman-owned business, Spazazz delivers a premium aromatherapy experience you can trust.
Dead Sea Salt (Spa-Approved Versions)
- Description: Some manufacturers offer Dead Sea salt blends that are filtered and safe for spas.
- Benefits: High in minerals, offers skin and muscle therapy.
- Note: Only use hot tub-specific versions—raw Dead Sea salts may still contain particles that can clog filters.
We recommend using Spa Depot Dead Sea Mineral Salts.
Spa Depot’s 100% natural Dead Sea mineral salts offer a premium spa experience, perfect for both hot tubs and bathtubs. Harvested from the Dead Sea in Israel, these fine white crystals dissolve quickly, making them safer for spa surfaces than coarse alternatives.
Rich in therapeutic minerals like magnesium and potassium, they help soothe sore muscles, ease dry skin and eczema symptoms, and support full-body detox. Packaged in a convenient resealable 5 lb. bag, this product is ideal for hydrotherapy and a relaxing, natural soak.
Ozonated Water or Mineral Sanitizer Systems
- Description: These systems naturally soften water and reduce the need for harsh chemicals, creating a more comfortable soak.
- Benefits: Gentler on skin, easier to maintain, and equipment-friendly.
We recommend using Nature2 Spa Mineral Sanitizer.
The Nature2 Spa Mineral Sanitizer is a natural and effective way to keep your hot tub water clean and clear. Designed for spas up to 500 gallons, these easy-to-use sticks drop directly into your spa’s filter and work with any flow rate.
Using mineral bed technology, they reduce the need for harsh chemicals like chlorine and bromine, leaving your water feeling soft and free of strong odors. Each stick lasts up to four months, and this 2-pack provides an extended, hassle-free solution for healthier spa water.
Why is Epsom salt safe in bathtubs but not hot tubs?
Epsom salt is safe in bathtubs but not in hot tubs because of how the two systems are designed and used:
Why It’s Safe in Bathtubs:
- No internal components: Bathtubs don’t have jets, pumps, filters, or heaters that can be damaged by salt buildup.
- Short-term use: The water is drained after each bath, so there’s no long-term exposure or buildup of minerals.
- No water chemistry to maintain: You don’t need to balance pH, alkalinity, or sanitizer levels in a bathtub like you do in a hot tub.
Why It’s Risky in Hot Tubs:
- Circulating system: Epsom salt can cause scaling or clogging in jets, pumps, and filters over time.
- Corrosion risk: Magnesium sulfate may corrode metal components such as heaters and fittings, especially at high temperatures.
- Water chemistry disruption: Epsom salts throw off the delicate balance of pH and alkalinity, reducing the effectiveness of sanitizers and potentially leading to bacterial growth.
- Long-term exposure: Hot tub water is reused for weeks or months, which increases the risk of damage from salt accumulation.
In short: Epsom salt is fine for a single soak in a standard tub but can cause costly damage in a hot tub’s complex and sensitive system.
Frequently Asked Questions
Can I safely use Epsom salts in my hot tub?
No, Epsom salts (magnesium sulfate) should not be used in a hot tub unless your hot tub manufacturer explicitly states it’s safe. Epsom salts can damage the internal components of your hot tub by causing corrosion, scaling, and chemical imbalances, which may also void the warranty.
What happens if I accidentally put Epsom salt in my hot tub?
If you’ve added Epsom salt to your hot tub, drain the water immediately, flush the system, and refill with fresh water. The sooner you act, the more you reduce the risk of damaging heaters, jets, and other components. Be sure to check for signs of corrosion or clogging after cleaning.
Are there any hot tub-safe alternatives to Epsom salt?
Yes. Many brands offer spa-safe aromatherapy crystals, liquids, or mineral additives designed specifically for hot tubs. These provide relaxation and therapeutic benefits without affecting water chemistry or damaging components.
Can I use Epsom salt in a saltwater hot tub system?
No. Saltwater hot tubs use sodium chloride (table salt), not magnesium sulfate (Epsom salt). Epsom salts are chemically different and are not compatible with saltwater systems unless explicitly approved by the hot tub manufacturer.
Don’t Put Epsom Salt in Hot Tubs, Just in Bathtubs
We hope we have explained why putting Epsom salt in a spa is not advisable.
It will not only damage the components in your hot tub but may also cause skin irritations when mixed with water sanitizers.
Epsom salts are best used in bathtubs where you can drain them after soaking.