Which of the following is not a responsibility of installers of hydromassage bathtubs?

The responsibility of installers of hydromassage bathtubs primarily revolves around ensuring that the electrical aspects and safety features are appropriately integrated into the installation. This includes ensuring safe electrical connections to avoid hazards such as electrical shock, conducting proper bonding to meet the grounding requirements, and adhering to the National Electrical Code (NEC) regulations to promote safety.

Conducting regular water quality tests, however, falls outside the scope of the installers' responsibilities. Regular water quality testing typically pertains to maintenance and operation, which is the responsibility of the owner or service personnel who manage the ongoing use of the hydromassage bathtub. The primary focus for installers during the setup is on installation practices rather than the subsequent health and safety checks of the bath water itself. Therefore, this context emphasizes that ensuring water quality is not a part of the installation responsibilities.