What is a sensory deprivation tank (isolation tank)? A sensory deprivation tank, also called an isolation tank or flotation tank, is used for restricted environmental stimulation therapy (REST). It is a dark, soundproof tank that is filled with a foot or less of salt water. The water in a sensory deprivation tank is heated to skin temperature and nearly saturated with Epsom salt (magnesium sulfate), providing buoyancy so you float more easily. You enter the tank nude and are cut off from all outside stimulation, including sound, sight, and gravity when the tank’s lid or door is closed. As you float weightless in the silence and darkness, the brain is supposed to enter into a deeply relaxed state. Sensory deprivation tank therapy is said to produce several effects on the brain, ranging from hallucinations to enhanced creativity. flotation tank, your body absorbs these minerals and your body’s magnesium and sulfate levels increase. This helps to calm your nervous system and enhances your body’s natural ability to heal. The deep relaxation state the you enter when floating helps to reduce stress by lowering cortisol levels. Blood flow is stimulated and endorphins are released. Endorphins are chemicals in the brain that reduce feelings of pain and trigger positive feelings. Studies have shown that floatation therapy can even help with depression. The endorphins released during a float last beyond the float session itself.