Die-hard hot tub lovers use their relaxing haven all year long. They understand the benefits of sitting in warm water and letting the jets massage worn-out muscles. Sitting in the deep basin with their head reclined back can be a nightly ritual alongside brushing their teeth. One caveat to year-round use is quicker heat loss during winter’s cooler months. The more heat that is lost, the higher the utility bills. Those dedicated to keeping the tub open may find that…