For a hot tub on your deck, you need sturdy and proper support to prevent any structural damage. A minimum of 75 pounds per square foot is recommended, increasing to 100 pounds per square foot for larger tubs. Ensure your deck is built with strong joists and a solid foundation, capable of handling the additional weight. It is advisable to consult a structural engineer or a professional contractor to assess your deck's capacity and make any necessary adjustments. The support required depends on the size and weight of the hot tub. It is essential to follow the manufacturer's guidelines and local building codes to ensure proper support to maintain the integrity of your deck and avoid any accidents. Remember, a well-supported deck will allow you to enjoy your hot tub safely for years to come.