Isolation tank


An isolation tank, often referred to as a sensory deprivation tank is a pitch-black, light-proof, soundproof environment heated to the same temperature as the skin. Flotation tanks are widely advertised as a form of alternative medicine, but beneficial health effects are unproven. The tank is filled with 10 inches of water which contains enough dissolved Epsom salt to create a specific gravity of approximately 1.275. This environment allows an individual to float effortlessly on the surface of the water. The primary function of the isolation tank is to eliminate as many of the external senses as possible. They were first used in 1954 to test the effects of sensory deprivation.

History

The isolation tank was developed in 1954 by John C. Lilly, a medical practitioner and neuropsychiatrist. During his training in psychoanalysis at the US National Institute of Mental Health, Lilly experimented with sensory deprivation.
Widespread commercial interest and use of the isolation tank didn't occur until 1972, when Glenn Perry, a computer systems programmer, began selling the first commercial tanks after he attended a five-day workshop by Lilly.
In 1981, there were about $4 million in sales and rentals in the industry, and expectations were that the market would grow, spurred by the film Altered States, which came out in 1980. According to one source in the industry, in the 1980s the rise of AIDS and the fear of shared water reduced demand for flotation centers. By 2013, flotation was more popular in Europe than the US, but had undergone some growth in the area around San Francisco; at that time a low-end tank cost about $10,000, and an hour-long flotation session cost about $70.

Notable users