If the cost of the electrical is a concern and it’s a long run between the panel and tub, you may want to consider using aluminum conductors. Aluminum Teck cable is half the price of copper, you can direct bury it and is a huge savings when used for long runs, especially when you you have to start increasing the size to take voltage drop into account.I recently used Aluminum Teck cable to feed a 100 amp panel in a barn that was almost 300‘ away from the main house and saved the guy a few thousand dollars.