Understanding Float Tank Solution Chemistry
To float so with zero effort, the float tank solution must fully offset the user’s body mass, achieving neutral buoyancy.
As a rule of thumb, float tank solution should have specific gravity (SG), or density, of between 1.23-1.30 in order for users to float effortlessly on top of the water. (For reference, the Dead Sea has a specific gravity of 1.3). At this density, it’s impossible for humans to fully submerged without the addition of external weight.
Floating: Achieving Buoyancy
The average float tank needs between 800-1,000 pounds of magnesium sulfate (epsom salt) with 150 to 200 gallons of water to create a between 25-30% salt solution to achieve a specific gravity between 1.23-1.3.
While it’s possible to increase the density of water by other means, magnesium sulfate is the standard ingredient in float tank solution for many other reasons.
The Role of Magnesium Sulfate in Floating
For one, magnesium sulfate is abundant, inexpensive, and reusable. At around $20 per 50 pounds, under normal circumstances and with proper maintenance, you can reuse your float solution indefinitely.
In addition, magnesium plays a key role in nerve transmission and neuromuscular conduction within the body. Magnesium deficiency, often caused by excessive fluid loss from exercise, can lead to cramping, mental confusion, convulsions, and interruption to the digestive system.
Although magnesium is usually taken in by dietary practices, there is some evidence to suggest that it can be absorbed through the skin during the act of floating for extended periods. Arguably the most important role of magnesium sulfate outside of increasing float solution density, is its antimicrobial properties.
The Impact of Magnesium Sulfate on Cellular Chemistry
The surface of the earth is roughly 70% water, yet as the old adage “water, water everywhere, but not a drop to drink” suggests, in raw form its not suitable for consumption. This is because the salt content of ocean water is higher than what’s found within the body, and albeit, counterintuitive, drinking salt water draws water out of the cells. In mammals, it doesn’t take much to lead to diarrhea, dehydration, and the shutting down of the nervous system.
But the impact of highly saline water does not stop with just human cells. The chemistry of any organism with a semipermeable cellular membrane, no matter how complex or simple it may be, will be altered in a highly saline environment such as in float tank solution. For bacteria and viruses, this disrupts the process of reproduction that is essential for sustained growth, though the time it takes to do so is not universal among organisms.