Quick Answer: Hot tub maintenance comes down to four clocks: every soak — test the water with a strip and top up sanitizer (chlorine 3–4 ppm or bromine 4–6 ppm); every week — shock the water and hose-rinse the filter cartridge; every month — deep-clean or replace the filter and rebalance alkalinity; every 1–3 months — drain, flush the plumbing, wipe down the liner, and refill. Follow that schedule and an inflatable or plug-and-play spa stays clear and safe on about 10 minutes of work a week.
A hot tub doesn’t fail dramatically — it drifts. Water goes from crystal to cloudy, the filter quietly clogs, the heater works harder, and suddenly the tub you loved is a chore. The fix is a boring, repeatable schedule. Here’s the full routine for inflatable and plug-and-play spas, task by task, with the handful of products that make it painless.
The maintenance schedule at a glance
| Frequency | Task | Time | What you need |
|---|---|---|---|
| Every soak (2–3×/week) | Test water, top up sanitizer, secure cover after | 2 min | Test strips, sanitizer |
| Weekly | Shock the water, hose-rinse filter, wipe waterline | 10 min | Shock, garden hose |
| Monthly | Deep-clean or swap filter, check alkalinity & hardness | 15 min | Filter cleaner, spare cartridge |
| Every 1–3 months | Drain, flush plumbing lines, clean liner, refill & rebalance | 1–2 hrs | Line flush, soft cloth |
According to the CDC, hot-tub water needs free chlorine of at least 3 ppm (or bromine at least 4 ppm) and a pH of 7.2–7.8 to reliably kill the germs behind hot-tub rash — which is why the every-soak test strip, the smallest task on this list, is also the most important one.
Every soak: test, dose, cover
Before (or right after) each soak, dip a test strip and read sanitizer, pH, and alkalinity. If sanitizer is low, add a measured dose; if pH has drifted out of 7.2–7.8, nudge it back. Which products do what — and which to buy — is covered in our hot tub chemicals guide; this guide is about when, that one is about what.
AquaChek Spa Test Strips (6-in-1)
- One dip reads everything you need to know before dosing anything.
- Testing 2–3× a week catches drift before it becomes cloudy water.
- A 50-strip bottle covers a full season of routine testing.
Maintenance means rebuying strips, filters, and sanitizer all season long — try Prime free for 30 days and those repeat orders ship free in two days instead of becoming a pool-store errand.
Then put the cover back on, every time. Per the U.S. Department of Energy, most of a spa’s standby heat escapes from the water surface, so a secured insulated cover is the single biggest lever on your monthly running cost — it keeps heat in, debris out, and your sanitizer from burning off in sunlight.
Weekly: shock and rinse the filter
Once a week, add a dose of shock (non-chlorine MPS lets you soak again in about 15 minutes) to burn off the sweat, oils, and lotions your sanitizer leaves behind. Do it with the pump running and the cover off for 20 minutes.
While the shock circulates, pull the filter cartridge and blast it with a garden hose, fanning the pleats apart. Intex recommends rinsing its PureSpa cartridges every 1–2 weeks — a clogged filter is the number-one reason inflatable-tub water turns cloudy and the pump strains. Wipe the waterline with a soft cloth or spa-safe scum sponge while you’re at it.
Replacement Filter Cartridges (Intex Type S1 / SaluSpa VI)
- Small inflatable-tub cartridges are consumables — replace every 4–8 weeks.
- With spares on hand you swap in a dry one and deep-clean the other on your schedule.
- Multi-packs cost a fraction of pool-store singles; match your tub's type (Intex Type S1, SaluSpa Type VI).
Monthly: deep-clean the filter, check the slow chemistry
A hose rinse clears debris but not the body oils soaked into the pleats. Once a month, soak the cartridge overnight in a filter-cleaner solution, rinse thoroughly, and let it dry — or simply rotate in a fresh spare. Check total alkalinity (80–120 ppm) and calcium hardness on your strip too; they drift slowly, but when alkalinity is off, pH refuses to hold steady.
Shop filter cleaner on Amazon →
Every 1–3 months: drain, flush, refill
No amount of chemistry fixes old water. Dissolved solids build up with every dose until the water resists balancing — the cue to start fresh.
When exactly? Use the spa industry’s standard drain-interval formula: gallons ÷ 3 ÷ daily bathers = days between drains. A 250-gallon inflatable tub with two daily soakers works out to roughly 40 days; a lightly used plug-and-play spa can stretch to 3–4 months.
The drain-day routine:
- Flush the plumbing first. Add a line-flush cleaner and run the jets for 15–30 minutes — it purges the biofilm hiding in the pipes that would instantly recontaminate fresh water.
- Drain using the tub’s valve or a submersible pump (grey water only, once chlorine has dropped — check local rules).
- Wipe down the liner or shell with a soft cloth and diluted spa surface cleaner. Never use household cleaners on an inflatable liner; residue foams and throws off chemistry.
- Refill through the filter housing if possible (fewer airlocks), then rebalance in order: alkalinity → pH → sanitizer, as covered in the chemicals guide.
Spa Line Flush Cleaner (Ahh-Some / Oh Yuk)
- Run before every drain — pipes hold the gunk your test strip can't see.
- A small jar handles multiple drain cycles on a 200–350 gallon tub.
- Fresh fills stay balanced noticeably longer after a proper purge.
Seasonal extras
- Summer: UV is hard on liners and covers — a spa cover protectant wipe-down every month or two keeps the vinyl from cracking.
- Winter: an inflatable tub in a cold climate needs freeze protection and a few extra habits — our winter inflatable hot tub guide covers which tubs handle it and how to run them.
- Going away? Don’t shut a tub off in freezing weather; either keep it heated at a low setpoint or drain it fully. A frozen pump is a dead pump.
The cost of doing it right (and wrong)
The whole routine — chemicals, replacement filters, the occasional line flush — runs $20–$50 a month on top of the $30–60 a month in electricity a typical inflatable or plug-and-play spa uses (see the full running-cost breakdown). Skipping it isn’t cheaper: a neglected filter makes the pump and heater work harder, cloudy water takes triple the chemicals to rescue, and a biofilm-fouled tub often means a full drain plus purge anyway. For the gear side of the routine — covers, steps, spare filters, ground mats — see our best hot tub accessories roundup.
The bottom line
Hot tub maintenance is four clocks: test every soak, shock and rinse weekly, deep-clean monthly, drain quarterly-ish. Ten minutes a week beats an afternoon of rescue chemistry every time. If you’re still choosing the tub itself, start with our best inflatable hot tub roundup or the best plug-and-play spas — and since every task above involves something you rebuy, it’s worth checking whether Amazon Prime is worth it for hot tub owners before you stock the shelf.