Flotation tanks

woman floating in water

What are flotation tanks?

Their popularity has been growing in recent years, sought for their purported ability to relax and de-stress the body and to quiet and open the mind. Flotation tanks—also identified as “sensory deprivation tanks” or “restricted environmental stimulation therapy”—allow people to lie on top of ten inches or so of water that’s warmed to body temperature and filled with enough Epsom salts to guarantee complete body buoyancy, inside an enclosure that can block out all light and most sound. Typically offered in professional spa settings or specialized facilities, flotation tanks are usually rounded rectangular pods that are just large enough to allow a single person to lie spread out atop the water or sit up comfortably inside.

Some people who are withdrawing from psychiatric drugs have found that flotation tanks help ease anxiety, deepen relaxation, and offer relief from a variety of symptoms. Notably, though, others report that even the thought of getting into a pitch-dark, soundproof chamber is anxiety-inducing, and users add that it’s not uncommon to experience altered states, including visions, auditory hallucinations, and out-of-body sensations. Indeed, flotation tanks were originally developed in the 1950s by neuroscientist John Lilly specifically to study the effects of sensory deprivation on the brain and human experience. If you have any concerns but still want to try, just ask the facility managers about options – most tanks allow users to prop open the door with a towel or other item to allow a little light and sound in, and some even come with optional intercoms, lights and music speakers.

They’ve seen a resurgence in recent years, sought for their purported ability to relax and de-stress the body and to quiet and open up the mind. Flotation tanks—also known as “restricted environmental stimulation therapy”, or REST—allow people to lie on top of ten inches or so of body-temperature water filled with enough Epsom salts to guarantee buoyancy, inside an enclosure that can be completely or partially free of light and sound as controlled by the person using it. Offered in professional spa settings, flotation tanks range in size from a kind of pod that’s large enough to sit up in to a small room-like enclosure tall enough to stand in.

Promoters of flotation tanks cite small, preliminary studies suggesting that the practice may lower blood pressure, pain, and stress hormones (such as cortisol) and offer a shortcut to a meditative state or relaxation response. They point to the tanks’ unique environment allowing users to calm their senses of vision, hearing, and touch while experiencing a sensation of weightlessness.

Some people who are withdrawing from psychiatric drugs have found that flotation tanks help ease anxiety and offer relief from other symptoms, perhaps due to the respite from sensory stimulation. Other people may find that even the thought of getting into a flotation chamber is anxiety-inducing (although those who are prone to claustrophobia should know that it’s possible to use the tank with the door cracked or completely open, and with the lights on).

Note that it’s not uncommon for those who use flotation tanks (even if they keep some lights on) to experience altered states, including visions, auditory hallucinations, and out-of-body sensations. If that’s a concern for you, you may want to consider in advance whether that would be a desirable outcome in your case. 

Flotation tanks are generally reserved for 60- or 90-minute sessions that typically cost $50 to $100. While some proponents suggest that the benefits accrue with repeat sessions, that may or may not be financially feasible. If you do opt to try a flotation tank, it’s a good idea to do some research first. Feel free to ask questions of the facility and follow recommendations for making the experience as comfortable as possible.
 


Where can I find more information?

  • Many large cities in North America and Europe have facilities with flotation tanks that can be found through web searches. Sessions typically cost between $50-$150 for 60-90 minutes.
     
  • A brief history of the invention and development of flotation tanks, and discussion of some of the science related to them.
     
  • More detailed information about neuroscientist John C. Lilly and his research into the effects of isolation tanks.