How clean is a float tank, really?
It’s the question every first-time floater asks, and it’s a fair one. Instead of handing you our cleaning checklist, we’re going to follow one germ from the moment it hitches a ride into the tank. Spoiler: it has a very bad day.
When people picture a float tank, they picture a hot tub. That’s the wrong picture. A hot tub is warm, lightly salted water that’s easy for germs to live in. A float tank is closer to the Dead Sea.
The salt is only the first problem a germ runs into. After that comes hydrogen peroxide, a fine micron filter, UV light, and a daily hand cleaning. No single step does all the work. Together, they leave very little room for anything to survive.
Here’s the whole trip, from the germ’s point of view.
Mark, owner of Float Boston
Meet our germ. It’s been riding around on someone’s shoulder all day, and it’s about to get into a float tank.
Before anyone gets in the tank, they shower. Soap and water take most of what’s on the skin straight down the drain: sweat, oils, lotion, and a lot of our germ’s traveling companions.
Our germ is one of the lucky ones. It holds on through the rinse and slides into the water with the floater. It thinks it’s made it. It hasn’t.
Each of our tanks holds about ten inches of water with roughly 1,000 pounds of Epsom salt dissolved in it. That works out to around 30% salt. It’s why you float like a cork.
That’s bad news for our germ. The germs that make people sick are built for the inside of a human body, where the salt level is under 1%. Drop one into water this salty and osmosis goes to work: the salt pulls water out of the germ’s cell, and it shrivels. It can’t grow and it can’t multiply.
We won’t pretend the salt alone sterilizes the water. It doesn’t. What it does is make the tank one of the most hostile places a germ can land, so everything after this works on a germ that’s already in trouble.
A hot tub is a germ’s vacation. A float tank is a germ’s Dead Sea.
Floating in that salt is hydrogen peroxide, the sanitizer we use in every tank. Peroxide is an oxidizer. When it touches a germ, it attacks the cell wall, the proteins and the genetic material inside. For a virus, that means its outer coat and the instructions it needs to copy itself.
We like peroxide for a second reason too. When it’s done working, it breaks down into water and oxygen. There’s no chlorine smell, nothing to sting your eyes, and nothing left on your skin.
We test the water regularly to make sure there’s always enough peroxide in it to do the job, and a professional water technician checks every tank on a regular schedule.
When a float ends, the tank doesn’t just sit there waiting for the next person. For 30 minutes, every float, the pump pulls the water out and pushes it through a fine micron filter.
A micron is a thousandth of a millimeter. A human hair is about 70 of them wide. The filter catches the things you can’t see: skin cells, stray hairs, tiny bits of oil, and the particles germs like to cling to.
Our germ, weak from the salt and damaged by the peroxide, gets swept into the current.
On the same trip through the pipes, the water passes under ultraviolet light. UV-C is the same kind of light hospitals and water treatment plants use to disinfect.
It goes straight for the germ’s DNA or RNA and scrambles it. A germ that can’t read its own instructions can’t copy itself, so even if a piece of it is still floating around, it can’t make anyone sick.
And it isn’t one pass. Over those 30 minutes, the water keeps cycling through the filter and the light, again and again, before the next floater ever opens the door.
Salt, peroxide, filter, light. Every float. Before the next person steps in.
Say our germ found a hiding spot. Not in the water, but stuck to a wall above the waterline, or on the lid.
That’s why we clean every tank by hand every day. We wipe down the walls and surfaces and clear anything off the water’s surface. We change the filters on a set schedule, based on how many floats each tank has done, so they never get overloaded. And the shower rooms get cleaned too.
That’s the end of the road. Our germ is done.
We handle the water. Here’s what we ask of you, and why:
Anyone can say their tanks are clean. What matters is what actually happens to the water between you and the person before you.
At Float Boston, that’s salt, peroxide, a 30-minute filter and UV cycle after every float, and a hand cleaning every day. A germ doesn’t stand much of a chance. You just get to lie back and float.
Float Boston is at 515 Medford Street in Somerville, open every day from 7:30 a.m. to 9 p.m.
Your first float is discounted with the code firstfloat. Want to make it a habit? The beginner package is 3 floats for $169, and you get a 4th free if you use all 3 within 60 days.
Floating is a wellness practice, not a medical treatment, and nothing here is medical advice. If you have an open wound, a contagious illness or a skin condition, check with your healthcare provider before floating.
Give the gift of floating and help fight cancer at the same time only at Float Boston. Buy online and get a PDF or come in-store and get one of 2 limited time gift card designs.