You just can’t keep a good idea down. Widespread in the 1970s and ’80s, float tanks have once again gone mainstream. Here we explore why—and examine whether you should join the wave of people getting in on this trend.

What’s a Float Tank?

A floatation tank is usually a clamshell-shaped pod filled with roughly 10 inches of highly salinized water—with anywhere from 800 to 1,400 pounds of dissolved Epsom salt. This allows you to float partially submerged in the body-temperature water, with your face and the front of your torso above water and the rest of your body below.

When the pod’s lid is closed, it can shut out light and sound for nearly total sensory deprivation—although today’s tanks usually offer light and sound options that you can keep on the whole time or select for only a few minutes at the beginning and end of your float. Most float tank sessions are at least one hour long, to give you enough time to completely relax—which is the goal of floating.

Sensory deprivation is the key to getting the most out of the float, because it allows you to either fall asleep or enter a meditative state that studies have shown calms your nervous system and reduce cortisol, the stress hormone.

“Sometimes it takes a couple of sessions to get to where you can let go and relax,” says Wendy Skaalerud, co-owner of Inngi Float in Highlands Ranch, Colo. “But when you do, there’s nothing like it.”

Float Tank Benefits

There’s no single study proving floating to be a miracle cure for anything, but a large body of research suggests it may alleviate chronic pain, reduce depression and anxiety, lower blood pressure, and relieve PTSD symptoms—even up to six months after regular float-therapy sessions. Many athletes—including greats such as Steph Curry, Tom Brady and Joe Rogan—have turned to float tanks to enhance their physical and mental sports performance.

People use floating to achieve many different goals, Skaalerud says. “Some problem-solve; some meditate; Erik [her husband and co-owner] falls asleep. In fact, for some people with chronic pain, floating is the only place they can sleep comfortably, because there are no pressure points.”

Get Away from Your Senses

It’s estimated that 11 million bits of data bombard our senses every second. And though our bodies can process only a fraction of that data, the sheer volume of information we encounter—combined with the often-frenetic pace of our lives—can lead to stress. According to the American Psychological Association’s 2017 Stress in America report, stress kept nearly half of us awake at least one night in the past month.

The History of Floating

Scientists invented the first float tank in the 1950s to study whether people would lose consciousness when deprived of all sensory stimuli. In the 1970s, commercial float tanks came on the scene, only to diminish in popularity amid the 1980s AIDS scare, before people knew how the disease was transmitted. Floating has recently reemerged, replacing its hippie image with a modern spa vibe.