Finishing off a hard day with a long soak in a hot tub is a favorite dream. Images of low lights, soft music, and fluffy robes entice you to take one more dip before calling it a night. You can’t imagine a day without bubbles gently popping around your shoulders. Yes, you think this could be your paradise forever – or can it? Hot tubs make great investments, but how long they last depend on a few factors. Do you…