Once a hot tub is filled with water, electrical resistance heaters warm the water to between 100 and 104 degrees. A pump forces water through an intake hose to circulate. A valve diverter then ...

"I wanted to create a way to keep a hot tub covered during use to keep the water warm and free from debris," said an inventor, from Philipsburg, QC, Canada, "so I invented The Hottub Heat Saver Cover.