The buoyancy of water reduces pressure on joints and muscles, especially in the shoulders, neck, and lower back. Muscle tension is a common physiological manifestation of anxiety. The buoyancy of a spa hot tub relaxes muscles, reducing body pressure and thus lowering psychological anxiety.

Soaking in a spa hot tub for more than 15 minutes causes the hot water to dissolve the skin's lipid barrier, weakening its natural moisturizing barrier. The result is that while the skin feels moist for a short time after soaking, the moisture evaporates quickly, leaving a tight and dry feeling.

Studies show that bacteria multiply fastest in water temperatures between 35–42°C, which is precisely the operating temperature range of a spa hot tub. Therefore, if the water is not changed or cleaned regularly, each milliliter of water may contain hundreds of thousands to millions of bacteria and microorganisms.

To ensure efficient and safe operation, the following items must be kept away from the spa hot tub: Bubble bath liquid, shower gel, soap, shampoo Essential oils, aromatherapy oils, oil-based fragrances Food or beverages Pool chemicals Non-spa-specific cleaning agents etc.

The bactericidal effect of chlorine decreases significantly at pH > 7.8, while bromine remains effective within the pH range of 8.0–8.5. This means that users do not need to frequently adjust the water quality in a spa hot tub.

Adding magnesium, such as magnesium sulfate (Epsom salt), to the water in a spa hot tub is only acceptable if the salt content does not exceed the recommended range. Especially when the total salinity exceeds 1500 ppm, it may cause corrosion or damage to the internal components of the hot tub.