What is float therapy?

Float therapy — also known as sensory deprivation, flotation REST (Restricted Environmental Stimulation Technique), or isolation tank therapy — involves lying in a specialized tank or pod filled with 10 to 12 inches of body-temperature water (93.5 to 95 degrees F) saturated with approximately 800 to 1,200 pounds of Epsom salt (magnesium sulfate). This extremely high salt concentration creates a buoyancy that allows you to float effortlessly on the surface without any effort, similar to the Dead Sea. The enclosed environment is designed to minimize sensory input: the water matches your skin temperature so you lose the sensation of where your body ends and the water begins, the tank is pitch dark when the interior light is turned off, and the space is insulated from external sound. This combination of weightlessness and sensory reduction allows your nervous system to shift into a deeply relaxed state. Sessions typically last 60 to 90 minutes. The practice was developed by neuroscientist Dr. John C. Lilly in the 1950s and has since been studied extensively for stress reduction, pain management, and creativity enhancement. Modern float centers use sophisticated water filtration systems — typically UV sterilization, ozone treatment, and hydrogen peroxide — to maintain strict hygiene standards between sessions.

Reviewed by Chad Waldman, Analytical Chemist · Last updated May 2026

About Float Therapy