How Often Should You Drain and Refill a Hot Tub?

You can balance and sanitize all you want, but hot tub water still wears out. Knowing when to refresh it keeps everything clear and your equipment healthy.

The general rule

Drain and refill every 3 to 4 months for a typical home spa. The classic formula: divide the gallons by the number of daily bathers, then by 3 — that’s roughly how many days between changes. A 400-gallon tub used by 2 people works out to about every 10 weeks.

Signs it’s due sooner

• Cyanuric acid above ~50–75 ppm (stabilizer buildup).
• Total dissolved solids climbing and water looking dull.
• You’re fighting pH or sanitizer that won’t hold.
• Persistent foam, odor or cloudiness despite balanced chemistry.

Make it easy

A proper change includes a line flush to clear biofilm, a wipe-down while empty, and a fresh refill that’s balanced before you soak. Our drain & refill service handles all of it, and our Luxury plan includes three a year.

Prefer to skip the upkeep entirely? Get a free quote from Bubble Balance — we keep hot tubs crystal-clear across Wilmington and the Cape Fear coast on a simple monthly plan. Or call (910) 264-3361.