Hot Spring Grandee water volume and filled weight
The essentials
Water volume for the Hot Spring Grandee is about 455 gallons. The cabinet measures 100 by 91 inches with 38 inch walls, seating is rated for 7, and the working weight sits near 6,150 lb.
Its place in the lineup
Among the 54 hard-shell models on this site, the middle of the pack is 383 gallons in a 88 inch body. This entry brings 19 percent more water than the middle and comes in 12 inches wider than it, or 65 gallons behind every rated seat.
Loaded weight, itemized
Three ingredients decide the total: the structure (1,060 lb), the fill (3,795 lb of water), and whoever climbs in (7 adults, about 1,295 lb). Together they come to 6,150 lb or so, which works out near 97 psf underfoot. Work out any tub on the filled weight calculator.
What the heater will draw
To sit ready at 102 F through 50 F days, this volume sheds and replaces about 9.6 kWh daily (average cover assumed). Priced at $0.17/kWh you are looking at $50 a month, bracketed by $35 and $73 at the rate extremes. Model your own rate and climate on the running cost calculator.
The chemistry, pre-measured
No conversion needed: each figure below already assumes this tub's 455 gallon fill. Ounces by weight.
| To do this | Chemical | Amount |
|---|---|---|
| Raise total alkalinity +10 ppm | sodium bicarbonate | 1.1 oz |
| Raise free chlorine +3 ppm | dichlor granules | 0.33 oz |
| Raise bromine +3 ppm | bromine granules | 0.30 oz |
| Chlorine shock (+10 ppm) | dichlor | 1.1 oz |
Start from your actual readings
Add in small steps with the pump running, wait, then retest before adding more. Never mix chemicals together, and always follow your product label, which wins over any calculator.
Hot Spring Grandee spec sheet
- Fill volume455 gal
- TypeHard-shell
- Dimensions (in)100 x 91 x 38
- Footprint63.2 ft²
- Rated seats7
- Gallons per seat65
- Water weight3,795 lb
- Empty weight1,060 lb
- Filled + 7 adults6,150 lb
- Standby heat (est.)9.6 kWh/day
- Heat-up 55 to 102 F (est., 4 kW)13.1 h
The kWh and heat-up entries come from published physics, not measurement, assuming 102 F inside, 50 F outside, and an average cover.
What setup involves
Think in layers: base first (level, rated for 97 psf), then power (a dedicated 240 volt circuit installed by an electrician), then water. Heat-up from a cold fill is roughly 13.1 hours at 4 kW, ideal case, so fill in the morning for an evening soak.
Source
The 455 gallon figure is from the manufacturer's published specification: www.hotspring.com. Manufacturer site (current/NXT gen, 7 seats). Older Grandee was rated ~500 gal/6 person. Capacities vary with how high you fill and with seats and footwell; confirm against your own manual or a metered fill when precision matters.