I recieved a question about plumbing and electrical on spas.
Most of the time all you need is a solid platform that can hold the weight of the spa with occupants, a hose, and a dedicated 120V connection to enjoy a hot tub. Granted these are very nice tubs, but if you want powerful therapy then you need to buy a spa with 5 HP pumps that require 240V to run.
My wife and I moved into our new place and we did not have the 240 V hook up for one of our high horsepower models, so we placed a 120V spa on the back patio and plugged it into the outdoor receptacle, filled it with a hose.
We use Eco One with a 24 hour ozone generator and had nice water with no harsh chemicals, like bromine or chlorine. It stayed clear on Eco One and ozone for 18 months then we drained it.
The only disavantage to 120V is the heater is only 1500 watts and when the spa jets are turned on the heater goes off for that time. With a DAIT spa you do not have to worry about heat loss out of the cabinet, but from the open top, so we used a floating thermal blanket on top of the water and folded it back so the area where we were sitting was open, but the rest of the top of the spa water was covered. That increased the soak time in Colorado winter to 45 minutes before the water cooled down.
Since I own a hot tub company, eventually we put one of our super powerful therapy machines, a Haven Spas Moonbay with stereo lighting and extreme jets. For that I wired in the 60 amp 240 V GFCI. It is still filled with a garen hose and drained with a garden hose, no plumbing is required for "portable spas".