How magnesium works — and why Epsom salt matters
Magnesium runs hundreds of quiet reactions in your body, and most of us are running low. Here is how an hour suspended in saturated Epsom-salt water fits in.
Every float tank holds a small, strange ocean: somewhere around 500 kilograms of Epsom salt dissolved into a few hundred litres of water, dense enough that you cannot sink if you tried. That salt is what makes floating possible. But Epsom salt is not table salt — it is magnesium sulfate — and the magnesium part is doing quiet work of its own.
What magnesium actually does
Magnesium is one of the body's true workhorse minerals. It is a cofactor in more than 300 enzyme reactions — the chemistry behind muscle function, nerve signalling, steady heart rhythm, blood-sugar control and the production of energy in every cell. It also helps regulate the nervous system, nudging you toward the calm, parasympathetic side of things. When you are low, you feel it: tighter muscles, more cramps, restless sleep, a frayed sense of calm.
Most of us are quietly short
Here is the awkward truth: a large share of people don't get enough magnesium. Modern soils are more depleted than they once were, processed food strips it out, and stress, caffeine and alcohol all increase how much we burn through and excrete. You don't have to be clinically deficient to be running on the low side — and to feel the difference when you top up.
The salt that holds you up is also the mineral your body keeps running short of.
Where floating comes in
Suspended in warm, magnesium-rich water for an hour, your skin is in contact with one of the most concentrated magnesium baths you will ever encounter. Just as importantly, floating switches off the stress response that burns through magnesium in the first place. Whatever the precise contribution of skin absorption, floaters reliably report the hallmarks of a magnesium top-up: looser muscles, deeper sleep and a calmer baseline in the days that follow.
Quick recap
- Epsom salt is magnesium sulfate — not the same as table salt.
- Magnesium powers 300+ reactions: muscles, nerves, sleep and calm.
- Stress, modern diets and depleted soils leave many people running low.
- An hour in saturated salt water relaxes muscles and supports better sleep.
Float it forward
You could take a magnesium supplement, and many people do. But few of them come with sixty minutes of weightless, sensory-free quiet attached. That combination — the mineral and the deep nervous-system rest — is what makes a float at our Auckland centre feel less like a bath and more like a reset. If you're curious, our intro offer is the easiest way to try your first one.