The water in spa equipment typically needs to maintain a stable chemical balance, such as pH, alkalinity, and disinfectant concentration. Rainwater has different chemical properties, so it may affect these parameters after entering the water.

Many people believe that weight loss after a spa hot tub bath is due to "burning fat." In reality, the temporary weight loss is due to the body losing water, not fat. Therefore, while a spa hot tub can slightly accelerate calorie burning, it cannot replace exercise.

If you experience the following symptoms after using a hot tub, you should suspect bacteria in the water: • Skin rash, itching, burning sensation; • Folliculitis or pimple-like red spots; • Localized skin infection or pustules. These are often signs of a hot tub rash caused by bacterial contamination.

For people with heart disease, using a spa hot tub carries potential risks. • Patients with coronary heart disease; • Those with a history of arrhythmia or heart failure; • Those who have had a myocardial infarction; • People with pacemakers (must have their device's safety range confirmed by a doctor).

Provided proper maintenance, short-term idle periods generally do not adversely affect the structure of the swim spa tub. The key is to complete the necessary preparatory work before idleness, such as cleaning, draining, and disconnecting the power.

In unclean spa hot tubs, it often causes a skin condition known as "Hot Tub Folliculitis." This infection manifests as folliculitis, rashes, itching, and even pustules, usually appearing within 24 to 48 hours of exposure.