An isolation tank, sensory deprivation tank, float tank, float pod, float cabin, flotation tank, or sensory attenuation 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. The tank is filled with 10 inches of water which contains enough dissolved Epsom salt to create a specific gravity of approximately 1.25–1.26. 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.
