Sitemap
All 76 pages on the site, grouped by section, with one line on what each one does.
Calculators
- All calculators · Chemical dosing, water volume, filled weight, running cost, and heat-up time in one place.
- Chemical dosing calculator · Enter your gallons, a reading, and a target for the exact ounces to add.
- Water volume calculator · Estimate your gallons from shape and dimensions, allowing for seats and footwell.
- Filled weight calculator · What your tub weighs empty and filled, for deck and pad planning.
- Running cost calculator · Monthly electricity cost from size, set temperature, climate, and your rate.
- Heat-up time calculator · Physics-based heat-up time from gallons, temperatures, and heater size.
Sizes and models
- Hot tub sizes and dimensions chart · Typical sizes by seating, plus exact gallons, dimensions, and filled weight by model.
- 2-person hot tubs · Dimensions, gallons, and filled weights across 2-person models, from the size database.
- 4-person hot tubs · Dimensions, gallons, and filled weights across 4-person models, from the size database.
- 6-person hot tubs · Dimensions, gallons, and filled weights across 6-person models, from the size database.
- 8-person hot tubs · Dimensions, gallons, and filled weights across 8-person models, from the size database.
- Bestway SaluSpa Miami AirJet (2-4 person) · Dimensions, water capacity, and filled weight for the Bestway SaluSpa Miami AirJet (2-4 person) (177 gal, seats 4).
- Bestway Hollywood AirJet (4-6 person) · Dimensions, water capacity, and filled weight for the Bestway Hollywood AirJet (4-6 person) (240 gal, seats 6).
- Bestway Mauritius AirJet (5-7 person) · Dimensions, water capacity, and filled weight for the Bestway Mauritius AirJet (5-7 person) (362 gal, seats 7).
- Bestway St.Lucia AirJet (2-3 person) · Dimensions, water capacity, and filled weight for the Bestway St.Lucia AirJet (2-3 person) (160 gal, seats 3).
- Bestway Vegas AirJet (4-6 person) · Dimensions, water capacity, and filled weight for the Bestway Vegas AirJet (4-6 person) (247 gal, seats 6).
- Bullfrog X8 · Dimensions, water capacity, and filled weight for the Bullfrog X8 (486 gal, seats 8).
- Hot Spring Grandee · Dimensions, water capacity, and filled weight for the Hot Spring Grandee (455 gal, seats 7).
- Intex PureSpa Plus Bubble Massage (6-person, 85in) · Dimensions, water capacity, and filled weight for the Intex PureSpa Plus Bubble Massage (6-person, 85in) (290 gal, seats 6).
- Intex Simple Spa (4-person, 77in) · Dimensions, water capacity, and filled weight for the Intex Simple Spa (4-person, 77in) (210 gal, seats 4).
- Jacuzzi J-325 · Dimensions, water capacity, and filled weight for the Jacuzzi J-325 (360 gal, seats 5).
- Jacuzzi J-345 · Dimensions, water capacity, and filled weight for the Jacuzzi J-345 (370 gal, seats 6).
- Jacuzzi J-465 · Dimensions, water capacity, and filled weight for the Jacuzzi J-465 (360 gal, seats 5).
Guides
- All water-care guides · Every guide on one page: balance problems, clarity problems, equipment problems, and routines.
- Hot tub dosing chart: doses by spa size · Ready-computed chlorine, bromine, pH, and alkalinity doses by spa size, from the same math as the calculator.
- How to lower pH in a hot tub · High pH dulls sanitizer and scales surfaces. How much acid to add, and why alkalinity comes first.
- How to raise pH in a hot tub · Low pH stings eyes and corrodes metal. Sizing soda ash, and the alkalinity link.
- How to lower alkalinity in a hot tub · High alkalinity locks pH high and clouds water. The acid-and-aerate method that works.
- How to raise alkalinity in a hot tub · Low alkalinity lets pH bounce. How much baking soda your gallons need.
- How to lower chlorine in a hot tub · Too much chlorine to soak. How to bring it down safely, fast and slow.
- Cloudy hot tub water: causes and fixes · The five usual causes of cloudy hot tub water, ranked, and the fix for each.
- Foamy hot tub water: why and how to fix it · Why hot tub water foams, the quick knockdown, and the real fix that lasts.
- How to clean a hot tub filter · Rinse, soak, and replace: keeping the cartridge that keeps your water clear.
- How to drain and refill a hot tub · When to change the water, and a clean refill that balances fast.
- How to winterize a hot tub · Closing a tub for winter without a cracked pipe come spring.
- Hot tub water change schedule · How often to drain, and the simple rule that sets the interval.
- What temperature should a hot tub be? · A safe, comfortable set point, and who should go cooler.
- How long does a hot tub take to heat up? · What sets heat-up time, and the numbers for plug-in and wired tubs.
- Saltwater hot tubs vs chlorine and bromine · A saltwater tub is not chlorine-free. How salt cells work, and the honest pros and cons.
- Hot tub maintenance · The simple rhythm: what to do after each soak, weekly, monthly, and at each water change.
- Hot tub jets not working: the fixes · Weak or dead jets are usually an air lock or low water, not a broken pump. The fixes in order.
- How to clean a hot tub · The full deep clean: flush the plumbing, drain, wipe the shell, clean the filter, refill, and rebalance.
- Hot tub start-up chemicals · What to add to a fresh fill, and the order that keeps pH from bouncing.
- Chlorine vs bromine for hot tubs · Cost, smell, heat stability, and skin compared, and why bromine suits most spas.
- How to shock a hot tub · When and why to shock, chlorine vs non-chlorine, and how long to wait before you soak.
- Hot tub calcium hardness · The 150 to 250 ppm target, how to raise low calcium, and how to bring high calcium down.
- Hot tub not heating · Runs but will not heat? It is usually flow: a dirty filter, low water, or an air lock.
- Hot tub error codes · What flow, overheat, sensor, and dry codes mean on Balboa and Gecko packs, and how to clear them.
- Hot tub tripping the breaker · A GFCI that keeps tripping: a heater element, a pump seal, moisture, or an aging breaker.
- Hot tub overheating · Hotter than the set point: a stuck control, a bad sensor, low flow, or just a hot day.
- Hot tub leaking · Most leaks are at the plumbing, not the shell. How to find one, and what you can seal yourself.
- Hot tub smells · Musty, chlorine, or rotten egg: what each odor means and the reset that fixes most.
- Hot tub algae · Green or mustard algae means sanitizer fell behind. Balance, shock, brush, and clean the filter.
- White water mold in a hot tub · The tissue-like biofilm, and the full purge that clears it from the pipes for good.
- How much electricity a hot tub uses · Typical kWh a month, what drives it, and how to turn it into dollars on your bill.
- How much does a hot tub cost? · Purchase by tier, plus delivery, electrical, running cost, and chemicals. The full picture.
- How to move (or get rid of) a hot tub · Drain it, dolly it, move it on its side with enough hands, plus how to remove and dispose of an old tub.
- Hot tub pad and base options · Concrete, pavers, gravel, or a spa pad: what holds a filled tub, with real weights by seating size.
- Plug and play hot tubs: 110V vs 220V · What a plug-in 110V tub trades for the easy setup, and when 220V hardwiring pays off.
- Hot tub wiring and electrical requirements · GFCI, disconnect, wire size, and the other NEC rules to know before an electrician quotes the run.
Accessories and gear
- Hot tub accessories · The accessories that improve a soak, and the ones to skip.
- Hot tub covers · How to measure for a replacement cover, when to replace one, and why a tight cover cuts running cost.
- Hot tub steps · Matching step height to your cabinet, weight ratings, and materials that hold up outdoors.
- Cover lifts · Hydraulic, pivot, under-mount, and shelf lifters compared by rear clearance and effort.
- Gazebos and enclosures · Minimum interior spans computed from real tub dimensions, ceiling height, and lift clearance.
- Recommended gear · Test strips, sanitizer, shock, adjusters, clarifier, filters, and covers we like.
Filters and inflatables
- Filter cross-reference · Find a replacement cartridge by part number or brand: the matching Pleatco, Unicel, and Filbur numbers.
- Inflatable hot tub guide · What inflatable tubs cost to run, how many they fit, and how they compare to hard-side.
- Best inflatable hot tub · Intex, Coleman SaluSpa, and Bestway Lay-Z-Spa compared by budget, cold weather, and capacity.
Site
- Home · Balance the water, size your tub, and cut running cost. Free tools, no account, works offline.
- About · Who writes this, how the numbers are made, and how to report a wrong figure.
- How we check the numbers · The 17 build-time dosing assertions and the source library behind every figure.
- Corrections log · Every substantive correction to a published figure, dated.
- Sitemap · This page: every page on the site with a one-line description.
- Terms of use · The calculators and guides are general information, not professional advice.
- Privacy policy · No accounts, no data collected. Your tub volume stays in your browser.