Changing the water: how often, when sooner and how to do it

Short answer: as a guideline, change the water every 2 to 3 months with normal use, sooner with intensive use or many changing guests, and immediately once the water is saturated: cloudy despite a clean filter and good pH, foam, smell, or disinfection that no longer holds. Changing the water is not a punishment but the cheapest reset: put it in the calendar, combine it with cleaning the shell and start water treatment straight away on the fresh fill.

Why water ages

With every bath, skin oils, sweat, sunscreen, hair products and dust enter the water. Maintenance products break some of this down, but the dissolved residue accumulates. At a certain point the water becomes saturated: chemistry no longer binds, the pH can no longer be kept stable and the water starts to foam or smell. Changing the water is then the only answer; continuing to dose only costs money.

Guideline by use

This guideline assumes the weekly AquaFinesse rhythm, a clean filter and showering before bathing. Anyone who skips this needs to change the water sooner.

Signs to change sooner

• Cloudy water that does not clear after a filter cycle and a correct pH; see fixing cloudy water.
• Foam forming as soon as the pump or jets start.
• A musty or sharp chemical smell above the water.
• Disinfection that disappears completely within a day.
• A pH that can no longer be kept stable; see setting the water balance.
• After illness of a bather or after a period of standstill without maintenance.

The water-change protocol

1. Stop dosing a few days beforehand if you want to dispose of the water in the garden, so the disinfectant has broken down.
2. Heater off and cold. With a wood-fired bath, never empty it with a hot heater; switch off an electric element first. See wood-fired heater use and maintenance.
3. Drain via the ball valve at the bottom of the bath, with a hose connection to a drain, flowerbed or street gully.
4. Flush the pipework for a bath with jets or filter pipework: let the last tens of litres run out with the jets running, so loose dirt is carried out of the pipework.
5. Clean the shell and waterline with a soft cloth and a mild, non-abrasive product; rinse thoroughly. The protocol is in cleaning a jacuzzi shell and also applies to the hot tub shell.
6. Clean or replace the filter; backwash for a sand filter.
7. Fill well above the heater connections; check the fittings for leaks.
8. Set the water balance: first alkalinity, then pH, then the first weekly dose. Wait 30 minutes before the first bath.

Disposing of bath water

• Water without active disinfection (not dosed for a few days) may in most local councils be disposed of in small quantities in the garden or via the rainwater drain; if in doubt, check local rules.
• Not directly onto a lawn or flowerbed all in one go with 1,000 litres: let it drain slowly over a larger area or into a street gully.
• Never into a ditch or surface water.
• Lukewarm water is fine; boiling hot water should not go onto plants.

Topping up in between

Evaporation and bathers use up water. Top up with the garden hose to the usual level and then measure the pH; tap water has a different balance to your bath water. Topping up is not a substitute for changing the water: the dissolved residue remains.