Hot tub and swim spa water changes much faster than pool water: the volume is small, the temperature is high and several people may use it at once. Continuous monitoring of pH, ORP and temperature shows changes within hours instead of at the next test.
Why spa water changes so quickly
- Small volume: each bather adds far more to the water per litre than in a pool.
- High temperature: warm water uses up sanitiser faster and suits bacteria.
- Aeration: jets and air blowers raise pH by driving off carbon dioxide.
The values to watch
pH shows whether the water is balanced; ORP shows whether the sanitiser is keeping up; temperature explains how fast both are likely to change. Together they give an early warning long before the water looks cloudy or smells.
Why it matters for dealers
For hot tub dealers, a connected monitor turns a one-off sale into an ongoing relationship. The owner sees their water in an app – with the dealer’s name, website and support button right there – and the dealer can follow all customer tubs on one dashboard and offer water-care services.
EVVO Sense for hot tubs and swim spas is installed in the spa’s circulation pipework, so nothing floats in the water and nothing has to be removed when the cover goes on.
Frequently asked questions
Can a smart monitor be fitted to an existing hot tub?
Yes. An inline monitor such as EVVO Sense fits into the existing circulation pipework, usually during a service visit.
Does a hot tub monitor work in swim spas?
Yes. Swim spas use the same type of circulation system, and the same values – pH, ORP and temperature – apply.
How often should hot tub water be tested?
Manually, at least a few times a week. Continuous monitoring checks it around the clock and alerts the owner when something drifts.
Talk to EVVO
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