Hot tubs are one of the most common, yet sought-after elements of the modern backyard oasis. The joy of soaking in warm, soothing, bubbling water after a tough day is an experience whose roots reach back to ancient times.
Unlike the natural hot springs frequented by those early civilizations, hot tubs require a little more legwork. As with any major investment, a hot tub requires a certain amount of maintenance to keep it safe, healthy and enjoyable.
Thankfully, hot water maintenance doesnât have to be complicated and time-consuming. By following these five steps, you can make sure your dream hot tub is safely up and running whenever you feel like a relaxing soak.

1. Keep it Clean
Every hot tub requires sanitizers to keep water clean and safe. The most commonly used hot tub chemicals are chlorine and bromine, which work to sanitize and oxidize any contaminants in the water.
Chlorine
Chlorine is added to hot tub water in the form of âfree chlorine,â an active sanitizer and oxidizer. Ideally, free chlorine levels in your hot tub should range from 2 to 4 parts per million (ppm). Once present, the free chlorine reacts with a variety of contaminants and destroys them.
When free chlorine reacts with ammonia compounds (e.g. traces of perspiration or urine), it becomes a new form of the chemical, called âcombined chlorine.â Once it has taken this form, the sanitization process is much slower. As a result, chlorine odours begin to develop and other bather inconveniences, such as eye irritation, soon follow.
If total chlorine levels become higher than free chlorine levels, the combined chlorine must be eliminated. This is most commonly done by âshockingâ the hot tub with additional chlorine to raise levels to 10 ppm. The additional chlorine will oxidize or eradicate the combined chlorine, eliminating odours and other problems. Non-chlorine shocks are also available to remove combined chlorine, but they only serve to oxidize the water and eliminate organic waste; they will not sanitize the water.
Bromine
Similar to chlorine, bromine enters the water as âfree bromine,â the level of which should ideally range between 3 and 6 ppm. Free bromine can also combine with ammonia compounds; however, unlike chlorine, this reaction does not slow the bromineâs reaction time. As a result there is no need to differentiate between free bromine and combined bromine.
That said, bromine users still need to periodically âshockâ hot tub water with a non-chlorine oxidizer to keep it fresh and clear. Once this process is completed, be sure to wait for bromine levels to fall back to within the optimum range before you take a soak.