Most people should change hot tub water every three months. If you use the tub every day, have lots of guests or the water stays cloudy after shocking, change hot tub water sooner.
When to change hot tub water
| Use | Change water |
|---|---|
| Light use (1–2 people, a few times a week) | Every 3–4 months |
| Family use (most days) | Every 2–3 months |
| Heavy use or parties | Every 4–8 weeks |
| Inflatable hot tub | Every 4–8 weeks |
Signs it is time
- Cloudy water that won’t clear after shocking.
- Foam that keeps coming back.
- A strong chemical smell even with balanced levels.
- Chemicals stop working as they should.
How to change hot tub water
- Turn the power off at the isolator.
- Add a line flush cleaner the day before if you can.
- Drain with the drain valve or a submersible pump.
- Wipe the shell and clean or replace the filter.
- Refill through the filter housing to avoid airlocks.
- Power on, balance pH and add sanitiser.
Need supplies? See our hot tub chemicals and read chlorine vs bromine. If you are on a water meter or a private well, check local guidance from Uisce Éireann during dry spells.
Frequently asked questions
How often should you change hot tub water?
About every three months for most households, more often with heavy use.
Can I change hot tub water less often?
Yes, with careful water care, a clean filter and light use you may stretch it to four months.
How long does it take to drain and refill a hot tub?
About 2–4 hours, plus 12–24 hours to heat back up.
Where can I drain my hot tub water?
Onto a lawn once chlorine has dropped, or into a foul drain. Avoid draining into streams or surface water drains.
Keep your water clear
Chemicals, filters and starter kits delivered across Ireland.
