In view of the growing interest in the field of floating, an article that came a little more detailed about the subject of the operation and use of float tanks was called for some time. In Romania, starting in 2015, the number of float centers has started to increase gradually, and if in the first year of pioneering the articles on this subject could be counted on a few fingers, now things are totally different. Nearly 4 years after Aquarmony opened its first floating center in Brasov, a short search on Google after floating therapy or float tank returns hundreds of links now. However, many people are still surprised when they hear about this subject, still new to them, and the question naturally appears: what are they and how these tanks actually work ?

The “classic” definition is found on our web page also: Float tanks. Also known as a Samadhi tank or Isolation tank. They can be seen as a large bathtub or small pool containing one ton of water in which 500 kilograms of Epsom salts have been dissolved. Concentrated magnesium salts allow floating in the 25 cm height solution and support the body in a state of imponderability. The float tank is large enough for an adult to float without touching the edges of the bathtub. Water is always kept at body temperature to eliminate cold or heat sensations in contact with the skin. Through sound and visual isolation, the influence of these sensory stimuli that normally occupy most of the brain’s functions is minimized. Only relaxation and peace remain, and the healing at all levels can begin.

Well, this is the brief presentation. But, as they say, the key is in the details. And people ask: Well, if I dissolve some salt bags in a tub or even in an inflatable pool, is not that the same? Why do I need an entire automation and filtering system with a tank of thousands or tens of thousands of euro/usd to do that? The answer in short is: it can not be, and the main reason is the salt. The most important detail, when it comes to floating basins, is magnesium salt. Magnesium sulfate (MgSO4), commonly called Epsom salt, is the one that actually makes all the difference. First of all, it has nothing to do with the classic kitchen salt, that is, sodium chloride (NaCl). Then, the cost of a batch of magnesium salt, ie the 400-600 kg needed to fill a float tank, is somewhere between 400 and 800 euro/usd, depending on the salt quality and the volume of the tub.

So, if at a Jacuzzi or a hot tub after a bath, you just remove the plug and drain the water, here’s a little different. Considering the costs of the salts, the idea of ​​a floating tank is precisely to re-use them for as many sessions as possible. Properly maintained and using a well-designed sanitation and filtration system, salts can be used for hundreds or even thousands of floats, months or even years until they are taken out and recycled or replaced. Until then, they are cleaned, filtered and supplemented as needed, as they gradually consume with each floating session. During this time, they can be removed in a temporary container, with a dedicated pump, for the necessary repairs to the tub or the filtration and sanitation installation, then reintroduced into the tank.

Also with salts, especially with their extremely high concentration, comes another major difference of the float tanks from other swimming pools, Jacuzzi or hydro-massage bathtubs. Pumps and other equipment recommended and commonly used for treating and filtering pool water simply do not withstand that density. Some give up in a few months, others in a few hours. And here we had one of the greatest challenges in designing the filtration system at our Aquarmony tanks. There are, of course, pumping systems that are designed for the chemical plants, but they are at an exorbitant cost. And we are looking for a middle formula, economical but reliable at the same time, that we have finally found. After months of testing, with the associated costs, we have come to a system that allows tanks to function within parameters, with the reliability needed in the float centers for the general public, where any malfunction comes with additional time and money costs.

Another important reason why not every salt-filled bathtub automatically becomes a float tank is the ambient. Specifically, the cabin or enclosure where the bathtub is located and the way its walls behave to moisture and heat. And here also, the salts have an important word to say. Specifically, the density of the solution increases as it cools. That is, crystals are simply formed at the surface of the water or at the bottom of the tub, if the salts are allowed to cool from the 35°C required for floating to 23-25 ​​degrees as the ambient environment usually is. And the crystals, as you might have guessed, are all the more damaging to the pumps and the filtration system, to the extreme case that they can completely freeze the plumbing pipes and nozzles. In short, the salt solution in the float tank must be kept constantly at the required floating temperature.

Here are another series of constructive differences, if we were to compare a floating enclosure with a sauna for example. Sauna, as well as a Jacuzzi, is generally thought to work only as long as the user is inside, and isolation for moisture and temperature loss is less relevant. In the case of a floating cabin, however, in order to keep the solution in the tank constantly warm, the pump with the automatic filtration and heating system work constantly. And a better thermal insulation greatly reduces the maintenance costs of the tank. For example, Aquarmony tanks cost up to 50 eur/usd per month for constant solution heating. In addition, sound insulation also plays an important role in sensory deprivation. For this reason, in the walls of the float cabins we built, we have come to use the best material at the moment for sound insulation, namely the high density sponge, also known as HD Foam.

Also, depending on the thermal efficiency, the floating tanks are divided into two categories: those that benefit from constant under tank heating such as underfloor heating and those that have an inline heater coupled to the pumping system, which works only when filtering the solution. The advantage of the under tank system is obvious: the radiant heat under the tub (with the obvious condition of a good isolation made at the bottom of the tank) constantly warms the saline solution, without noise, so floating sessions longer than 2 hours can be done without problems. Even night-time sessions of 10-12 hours are possible without the need to start the circulation pump and without the solution cooling down. The disadvantage is the cost and complexity, because they usually have to be encapsulated inside the bottom of the tub when it is made. On the other hand, the inline heaters coupled to the circulation system are cheaper and bear higher powers for faster heating of the solution when needed. To benefit from maximum thermal efficiency, all Aquarmony tanks are fitted with both types of heaters.

Besides the pumping and heating components, the most important part of the re-circulation system is filtration and sanitation. But in this case, concentrated magnesium salts become an advantage, if it is to compare the float tanks again with a classic pool or Jacuzzi. At such salts density, microorganisms find it almost impossible to survive. In the float tanks, the density is similar to that of the Dead Sea. And this is where the “Dead Sea” gets its name – no bacteria can live in its high salinity conditions. To make things safer, however, the float tanks also use other methods of hygiene: mechanical filtration of the remaining particles in water, ozone, UV lamps, addition of hydrogen peroxide / chlorine / bromine, or a combination of these.

For our Aquarmony float tanks, we have opted for a combination of mechanical filters with ozone and UV lamp. The fact that some tank producers or float center owners choose to use chemicals in floating tanks, just like in public swimming pools, only makes us sad. First, the large amount of salt makes it almost impossible to measure the exact concentration of chemicals used. And these are harmful to the skin and breath even in public swimming pools, so the more harmful in a confined environment, such as a float tank, if they stay in water and air throughout the floating period. We use and strongly recommend ozone, which is a naturally occurring gas that disperses itself within minutes of stopping the ozone generator. By proper dosing and ventilation, it sanitizes both the water and the air in the enclosure, bringing even health benefits. And in combination with UV lamps in advanced oxidation, ozone gets tens of times stronger than chlorine in removing bacteria that may remain in the tank’s saline solution.

In addition to these main elements, details such as wall materials, the way in which the float cabin’s natural ventilation is designed, or ceiling heating to eliminate condensation and dripping during floating sessions also play an important role. Aquarmony currently has four custom designed models, each with its particular features: a float cabin – Aquarmony One, a float pyramid – Aquarmony Pyramid, a float room – Aquarmony Premium, a float pod – Aquarmony Infinity. However, the advantages and disadvantages of each construction variant are detailed in a separate article, with various Float Tank Types , where we also have a short comparison table between the main types of tanks. But remember, as they say, size does matter: usually in the case of float tanks, the size really makes a difference.