CleverSpa Onyx 4-Person Hot Tub

The Onyx is WhatSpa's 'Best Budget' pick and the least expensive route into a tub you can still run in winter. It seats four, runs 110 air jets and an 1,800W integrated digital pump/heater to 40°C across an 800L body, and - the reason it earns its place over cheaper rivals - includes 365 FreezeGuard so it isn't a summer-only purchase. Its indicative retail is around £249.99, though it moves a lot by retailer and season and is often discounted lower, so treat the figure as a guide rather than a fixed price. The compromises are real: WhatSpa notes slower heating, and lighter insulation means higher relative running cost per session, while CleverSpa is a smaller UK presence than Bestway's Lay-Z-Spa, so spares can be less widely stocked. It ranks last on overall merit, but it is the clear choice when budget or a smaller patio is the binding constraint.