Clean Looking and Smelling Tanks (A Comprehensive Guide)

by Sandra Calm with contributions from Emily Noren, Dylan Schmidt, and Graham Talley Recently, the New York Times released a mostly positive article on floating... But the opening line mentions that the tank smelled "like a used gym sock.” Today's guest post from Sandra Calm (co-owner of the Float Shoppe, my wife, who also happens to have a masters in nursing) walks us through why that darn smell appears, how to get rid of it, and, most importantly, how to prevent it from every rearing its ugly head in the first place! Smelly Tank No float center ever has to have a tank that smells like a used gym sock! Here’s an overview of the problem and easy steps to prevent or cure it.

What causes this smell?

Body oils, product residue, and skin cells are shed by each person who enters the float tank. Without getting too technical, these things contribute to the development of the characteristic locker room smell. Regular float tank maintenance procedures keep this problem away entirely. Here’s what you need to do!

Float Tank Maintenance 101

The best way to keep your water sparkling clean is to have excellent tank and water maintenance procedures in place from the moment you mix in your first batch of salt. The key components of maintaining your float tank are as follows: Sanitizers Whether you use hydrogen peroxide or another sanitizer, be sure you are keeping your levels consistently within the correct range. If you are using hydrogen peroxide, this means between 60 and 100 ppm. Do not ever allow your sanitizer to reach a reading of zero. Test several times each day, and document your levels and additions each time. We test before opening and after closing, adding hydrogen peroxide as necessary. Filter Changes Change filters regularly according to the volume of people using your float tanks. We have found a filter change every 30 to 40 float sessions works very well, which equates to once or twice per week for us. If you’re unsure, change your filters more often than you think you should. Filter Care Depending on your model of float tank, you may be using either disposable or reusable filters. If you are using disposable filters, that’s easy! Just replace them. Reusable filters, on the other hand, must be soaked overnight in bleach water solution then sprayed with a power sprayer and allowed to dry between uses. It works well to have at least two filters per float tank so you can switch one out for the other, allowing one to be cared for while the other is in use. Surface Care Bacteria and fungi love places that are warm and moist, just like the walls on the inside of a float tank. At least twice or three times per week, wipe down all interior surfaces of the float tank with a disinfecting solution such as bleach and water, ahydrogen peroxide spray, or medical-grade cleaner like Virex II. This will prevent the growth of any mildew or other things on the inside of the float tank. If your float tank develops condensation, dry off the interior surface every morning with a towel or a mop with an absorbent surface. Salt Levels Float tanks are incredibly inhospitable to microorganisms because the water is so dense with Epsom salt. At the correct density, water inside the cells of microorganisms is sucked out of the cell, essentially causing the cell to implode. Purchase a hydrometer, which measures the specific gravity of your water, and check the specific gravity of your float tanks at least twice per week. Make sure your water is kept at a specific gravity between 1.25 and 1.29. Below 1.25, floats aren’t quite floaty enough...At 1.3, the solution is so close to saturation the salt will have a greater tendency to come out of solution and crystallize. Not only do correct salt levels ensure good floats, they also keep microorganisms at bay. Balancing pH and Alkalinity While this topic requires an entirely separate post, the short story is: keep your pH and alkalinity balanced. Measure regularly. Generally, we have found that required adjustments can be made mostly with Epsom salt (which is mildly acidic) and sodium bicarbonate (baking soda, which, in short, helps the solution to stay balanced). Managing Skin Oils The body produces natural skin oils at all times. There are several aspects of managing skin oils: Showers Ensure your clients are taking a rinsing shower before each float, using soap to wash from head to toe. We recommend Dr. Bronner’s liquid soap, which you can cut with 25% water to reduce costs. Mixing the Water Because skin oils are less dense than the water, they float on the surface of the water and can escape filtration unless they are mixed into the water.. Ensure your filtration system “roughs up” the top of the water to promote adequate mixing of the solution during filtration. If there is no disturbance to your water as it filters, perhaps you could direct the filtration exit port towards the surface of the water to create a disturbance in the surface. Otherwise, you will need to manually mix the solution while it is being filtered using, perhaps, a large pool skimmer wand. Oil Absorbing Sponges Leaving an oil absorbing sponge such as The Scumbug in your float tank overnight helps to absorb excess skin oils. If your float tank manufacturer approves it, they may also be placed within your filtration system. The latter technique assumes adequate mixing of the water, however. Skimmers Most float tanks are outfitted with a skimmer, designed to remove any hair or other large particles from the surface of the water. Oils have a tendency to stick together, and since hair is naturally coated with oil, removing hairs will pull oils as well from the surface. Enzymes and Flocculants Products like Spa Perfect are designed to break up oils, changing the way they behave in water and allowing them to be filtered out. Enzymes break down molecules. A flocculant causes small particles to group together into larger particles, allowing them to be filtered out. Managing Product Residue Anything on a client's body will end up in the water. Encourage your clients not to use shampoo or conditioner before they float, but to rinse their hair well with water, using Dr. Bronner’s if they have a lot of product in their hair. Most shampoos and conditioners have constituents such as sodium laureth sulfate which will leave a residue in the water, so look for products that are sulfate-free in case the client decides to use shampoo or conditioner beforehand anyways. Nature's Gate Shampoo and Conditioner are both wonderful, and we've found they work very well to remove salt after floating. As a sidenote: it’s generally substances from hair products that forms the ring at the waterline in float tanks, easily cleaned using a semi-rough sponge. Tracking Levels Recording all figures related to your float tank is essential for your awareness of trends and needs of the float tanks over time. We use Helm, which has excellent internal recording capabilities, including the option to graph levels over time and compare levels to each other. For example, you can see hydrogen peroxide levels vs. hydrogen peroxide additions on the same graph together. If you keep having a problem with one tank, sometimes correlations can help you to see what's happening.

How to Make the Smell Go Away

    Follow these steps to bring your tank back up to snuff, then be sure to implement all aspects of the maintenance list, above.
  • Filter all day during a maintenance day and for long times whenever possible.
  • Change filters and filter some more.
  • Double check to be sure all aspects of your filtration system are in proper working order.
  • Add a relatively large dose of sanitizer during a maintenance day, ensuring sanitizer levels are within normal range before returning to normal business hours.
  • Wipe down the inside of the float tank, paying close attention to every nook and cranny.
  • Balance all levels, starting with water, then salt, then sanitizer, then alkalinity (which affects pH), then pH.
Remember, everyone with a float tank has most likely faced this problem at some point or another. You can have clean, sparkling water all the time. If you’re struggling with your water, reach out to us and others in the industry. You are not alone, and we are all here to help!

Additional Resources

US Float Tank Association Tank Maintenance Schedule US Float Tank Association US Float Tank Standard Float Tank Solutions Health Department Essentials (Free) This article represents the best of our knowledge after running a commercial float center for four years. Additional ideas are welcome and will be added! Please email or comment below.