Rookie Spa

Inflatable Hot Tub Water Care for Beginners

By Jake Weber · Published September 11, 2026

Inflatable Hot Tub Water Care for Beginners

Nobody buys an inflatable hot tub because they want a chemistry hobby. You want to sit in hot water after work. But skip water care entirely and within two weeks you’ll be googling “why does my hot tub smell like a locker room” at midnight.

Here’s the good news: keeping the water right takes about 10 minutes a week once you understand one thing most guides get wrong.

The mistake almost every beginner makes

Most water-care advice online is written for full-size hard-shell spas — 400+ gallons. Your inflatable tub holds roughly 150-300 gallons depending on the model. That means every scoop of chemicals hits harder. Follow pool-sized or big-spa dosing and you’ll overshoot constantly: stinging eyes, bleached-smelling water, itchy skin.

Rule one: dose for YOUR gallons, in small increments, and test before adding more. Find your tub’s water capacity in the manual or on the box (it’s usually listed as “water capacity” — note some listings show the max fill, others the recommended fill).

The 4 things that actually matter

  1. Sanitizer (chlorine or bromine). Kills the stuff that makes water dangerous and smelly. Target: a steady 3-4 ppm free chlorine — the sweet spot that keeps both Bestway (2-4 ppm) and the CDC (at least 3 ppm) satisfied. Add it as tablets in the floating dispenser, not by tossing granules in: the SaluSpa manual specifically says to use tablets in the dispenser and to never drop chemicals straight onto the liner.
  2. pH. How acidic/basic the water is. Target 7.4-7.6 (7.2 is still okay). Too high and the chlorine stops working well; too low and it’s harsh on skin and parts.
  3. Total alkalinity. The pH’s shock absorber, keeps it from swinging. Target roughly 80-120 ppm. Adjust alkalinity before chasing pH.
  4. Filtration. The filter cartridge catches what chemistry can’t. Rinse it weekly; replace when it stays grey after rinsing. (A tired filter is also the top cause of the E02 flow error.)

That’s it. Everything else — clarifiers, defoamers, fancy minerals — is optional and usually a band-aid for one of the four above.

Your 10-minute weekly routine

  1. Dip a test strip (1 min). Read chlorine, pH, alkalinity.
  2. Adjust what’s off (3 min). Small doses: for a ~200-gallon tub, that’s a fraction of what a spa-size scoop suggests. Pre-dissolve any pH or alkalinity adjuster in a bucket of water and pour it in with the pump running — never straight onto the liner. Let it circulate 30+ minutes, re-test before adding more. Alkalinity first, then pH, then sanitizer.
  3. Rinse the filter (2 min). Unplug the pump first — Bestway’s manual says to unplug before any spa maintenance — then rinse the cartridge under the tap, refit it and plug back in. Swap in a dry spare if you keep one (you should — they’re cheap).
  4. Quick look at the water (1 min). Clear? Done. Off in any way? See below.

After heavy use (guests, kids, sunscreen day), give the water a sanitizer boost that evening — open the dispenser wider, or follow your product’s directions, dissolving it in water first rather than on the liner. Bather load is what eats your sanitizer.

When the water goes wrong

Cloudy? Don’t reach for clarifier first — that treats the symptom. In order: check pH (usually high), check chlorine (usually low), rinse the filter (pump unplugged while it’s out), and give it a few hours of filtration. Clarifier is the last step, not the first.

Foamy? Usually body products (lotion, detergent in swimsuits) building up. Rinse suits in plain water, shower before soaking, and if it persists, it’s telling you a water change is due.

Smelly (“skunky”)? That’s not “too much chlorine” — it’s usually spent chlorine (chloramines) plus organics. A proper shock dose and a filter rinse fixes most cases; if the smell returns fast, change the water.

How often to change the water? With 2 people using it a few times a week, every 4-8 weeks is a reasonable rhythm for these small tubs. Small volume = faster buildup than a big spa. If chemistry keeps fighting you, changing the water is faster and cheaper than chasing it with products.

Chlorine or bromine?

Chlorine tablets in the floating dispenser are the simple, cheap default, and what I’d start with. One thing to skip: stabilized chlorine — dichlor or trichlor, which carry cyanuric acid. It’s a pool staple, but the CDC advises against cyanuric acid in hot tubs; the heat and small water volume let it build up fast and stall your sanitizer. Bromine is gentler on skin and holds up better at hot-tub temperatures, though it’s pricier and comes in several forms (tablets, granular, two-part sodium-bromide systems) that each dose differently — so follow the directions on the product you buy. Start with chlorine; switch later if it bothers your skin.

A sane starter kit

You need less than the store wants to sell you:

Skip for now: clarifiers, defoamers, scents (many aren’t inflatable-safe — check the label), and anything called a “system” until you know what your water actually needs.

Water care question this guide didn’t answer? Tell me — the beginner questions are exactly the ones I want this page to cover.

Jake Weber

Jake Weber — Jake Weber is the pen name of Rookie Spa’s editor. I don’t sell spas or chemicals, and I’m not affiliated with any brand. Every guide here starts from the manufacturer’s manual, is cross-checked against the questions and fixes owners report most often, and is written in plain English for first-time owners — with a clear warning whenever something involves electricity or water safety.