The Hydro Massage System includes: a hydro pump with an in-line water heater, eco-friendly ozone sterilization system, hydro massage intensity dial control, and strategically positioned hydro jet system for targeted and effective massaging. The in-line water heater helps maintain the water temperature at constant level while bathing, if the water tank can produce enough hot water. It is suggested to upgrade to the largest available 75-gallon water heater to ensure enough hot water. Please consult with a professional contractor to determine if your water tank can provide enough hot water for a walk-in bathtub. Our ozone sterilization system is the most eco-friendly, chemical free disinfectant that can eliminate a wide variety of inorganic, organic, and microbiological bacteria. The sterilization system is especially helpful in eliminating odors and hygienic maintenance. The in-line water heater and ozone sterilization automatically engage when the hydro massage push control is pressed down when turning on your jets. The hydro massage intensity dial control allows you to adjust the strength of the water stream by adding more or less air into the hydro system.The Hydro Massage System’s most popular control system is the on/off push control because the buttons were designed to rise above the deck in order to make it easier to push. A smaller, digital controller is also available for the Air+Hydrotherapy Massage Package, but may be more difficult for elderly to see and operate.