While a sensory deprivation tank might sound very modern and new age, it was in fact invented by John C. Lilly in 1954.
Lilly, a neuroscientist and psychologist, pioneered zero gravity relaxation to explore human consciousness. What could happen if a human’s brain is starved of its senses and external stimulation?
He first experimented with wearing a diving mask that blocked out sound and light whilst being submerged in a water-filled chamber. By the 1970s he had refined his floatation tank to be more like the float tanks we know today.
We’ll discuss exactly what a modern float tank is, how it works, the benefits that can be enjoyed from float tank therapy, as well as some myths surrounding the surreal experience.

What is a Float Tank?
A floatation tank, synonymous with an isolation tank or sensory deprivation tank, is a large vessel typically filled with around 1000 litres of water and 550kg of Epsom salts.
The extremely high concentration of Epsom salts in the tank increases the water’s density and buoyancy. This allows you to effortlessly float on your back as if you are in the Dead Sea, with your body and head partially underwater.
A float tank is usually large enough for you to be able to stretch out fully without any body parts touching the roof, floor, or walls. Additionally, the tank is only around 50cm deep so you can easily sit on the bottom if needed.
In order to completely deprive you of all your senses, the float room is dark and soundproof. This encourages you to float into a quiet, meditative state. The Epsom salt solution is high in magnesium which has great benefits on the human body.
How Is Exposing Your Body to Magnesium Through Floatation Therapy Beneficial?
The main reason for the inclusion of Epsom salt for float therapy is because of its ability to allow the body to float. But, as a byproduct, it has many benefits that can improve health and overall wellbeing.
During floatation therapy, the magnesium from the Epsom salt is absorbed through the skin. The human body is clever enough to optimise its levels of magnesium, so they won’t get too high and become dangerous.
Here are some of the things that can improve with increased magnesium in the body thanks to a float session:
- Stress: magnesium helps to bind serotonin, also known as the happy hormone. Excess stress and adrenaline can be relieved thanks to increased magnesium.
- Relaxation: reduced stress can lead to feelings of well-being and deeper relaxation.
- Headaches: magnesium can ease and prevent headaches and migraines.
- Blood circulation: muscle and joint aches, inflammation and chronic pain can be typical symptoms of low magnesium. Increased blood flow can remove waste products quicker and more effectively and bring fresh oxygenated blood to the problem site.
- Heart health: increased magnesium and blood flow can prevent arteries from hardening, blood clots and can lower overall blood pressure.
- Bone health: magnesium assists with calcium absorption into the bones.
What Are the Main Benefits Of Sensory Deprivation?
Removing stimuli from the senses can be as simple as using a blindfold or ear plugs. In a float tank, all sights and sounds are removed as the tank closes you off from the outside world. (But don’t worry, if you’re claustrophobic you can leave the tank’s door open and there is a light that you can choose to leave on or off.)
The water inside the tank is heated to match the skin’s temperature. This makes it hard to figure out where your body is and isn’t touching the water, mimicking the feeling of floating in thin air.
The floating experience in the tank with the lights off restricts your vision, you can’t hear anything except your own breathing, there’s nothing to smell or taste, and you are completely buoyant in the salt solution. You are submerged in a feeling of zero gravity, without any concept of time or space, up or down, body or water.
So why would you want to undergo deprivation of your senses? After all, humans come with the five main senses to help us navigate our way around the world for a reason.
Well, float therapy can allow a deep relaxation that is unachievable in the normal world. Besides all the other benefits that are a result of floating, it’s the amazing experience of complete and total relaxation that many people float for.
The relaxation achieved is even comparable to using anti-anxiety drugs or meditation. Floatation therapy allows people with anxiety to be more aware of their bodies. Anxiety sufferers sometimes feel as though their heart is beating out of control, and lying completely still and deprived of sensory stimulation allows you to really hear and focus on your own heartbeat and breathing to bring it back to a normal level.

Debunking Myths That Might Deter First Time Floaters
Many people miss out on this unique experience, because they knock it before they try it, and often don’t bother to do their research. Here are two common myths regarding float therapy that simply aren’t true.
Float Therapy Is Dangerous
Even if you fall asleep in a floatation tank, it is unlikely to be dangerous as the chances of drowning are slim to none. The Epsom salt results in such buoyancy of the body that it is extremely difficult to turn over unintentionally. So even if you relax so much that you drift into sleep, you will remain on your back.
However, floating when under the influence of alcohol or drugs may increase its danger, so it is still advised to engage the services of a floatation tank free from influence of such substances, and as advised by your doctor.
The other time when using float therapy isn’t advised because it may have adverse effects is when you have illnesses such as:
- claustrophobia (though the majority of people with claustrophobia don’t have any issues once they realise that they are in control),
- contagious diseases like diarrhoea,
- uncontrolled epilepsy,
- kidney disease,
- low blood pressure, or
- open wounds.
Floatation is even safe for pregnant women and even has numerous benefits thanks to being in such a highly relaxed state.
Float Tanks Are Dirty
Although many people can use a floatation tank over the course of the day, it’s highly unlikely that they will be dirty. The excessive magnesium sulphate concentration prevents organisms from multiplying and kills them off over time.
Additionally, floatation tanks are cleaned and sanitised to a level higher than pools. Throughout the day and between clients, the water is filtered through a micron filter which is 1/10 the size of a hair, and hydrogen peroxide is used to sanitise the water in a low dose that is paired with a UV light to kill all bacteria.
At Feel Good Nation, we also ask clients to practise good hygiene and shower both before and after a floating session.
Lying in a Float Tank Is Boring
We are exposed to overstimulation daily in our normal lives. A float tank offers 60 minutes of complete nothingness. While some might very well find that boring, the majority of people find that euphoric. It is a great way to do a mind dump so that you can sleep better at night. You’ll have less racing on your mind as you have already processed it all.
Theta waves are produced by the brain just before we fall asleep or wake up. The theta state can promote creativity, inspiration, insight, memory recall, and decreased stress and anxiety. The brain naturally produces these theta waves while floating.
We normally only experience theta waves for very short bursts, but floatation tanks can encourage extended theta periods where we can visualise vivid mental images.
Key Takeaways
Merely one hour of floating in our Sydney float tanks can help you escape the stresses of everyday life and completely forget your location.
The peace of no noise, busyness or any other stimuli grabbing your attention can help you fully relax and feel amazing.
Besides feeling completely relaxed during and even after, floating in the magnesium solution can also increase blood circulation and aid in aches, pains and tension in muscles, relieve headaches, and improve heart and bone health.
If you’d like to discover the beauty of floating for yourself, or even if you are craving the feeling of being relaxed even if it’s just for an hour, contact us at Feel Good Nation during our opening hours to book an appointment and we’ll answer any more questions you might have.
DISCLAIMER
The information on this website is for informational purposes only. No material is intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your doctor with any questions you have regarding a medical condition or treatment before undertaking a new health regimen. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.