If you have a hot tub, you are very familiar with the issues related to the use of chemicals to sanitize your hot tub. The chemicals such as chlorine, bromine, pH up, pH down, shock (hydrochloric acid), clarifier and de-foamers are all used to sanitize and clarify the water. This concoction of hazardous materials produces vapors and substances that cause respiratory irritation, skin rashes, discoloration of clothing and environmental issues.
These chemicals need to be added continuously to be effective. After a short period of time the water becomes saturated and the chemicals are no longer effective or the chemistry becomes so unstable that it is impossible to balance to the required levels.
When the water becomes chemically saturated the water must be changed. All of the chemical laden water is typically discharged to the environment with complete disregard for its effect. In addition to the environmental issues, the hot tub must be refilled. Depending on the water source used for refill, the balancing act must begin again to adjust for hardness and iron content. Additionally, a significant amount of energy is consumed in pumping the water and heating the water from somewhere around 50º to 100º + degrees.