The Hydropool Self-Cleaning 579 is a 5-person hot tub that features a lounge chair that never floats. This hot tub is one of Hydropool's best-selling hot tubs because while 95% of customers buy a two-person hot tub, they often want the ability to fit four. With its roomy interior and tiered seating, the Hydropool 570 is roomy enough to treat you and four friends like royalty, while its European styling makes it a nice addition to everyone's hangout.