Choosing the right chemicals is important for maintaining a clean, safe, and enjoyable hot tub. Bromine and chlorine are the two sanitizer options, each with unique properties that make them better suited for different situations. Individual reactions should also be considered: some people may react to bromine while others may react to chlorine, and vice versa.
Chlorine or Bromine, which is better?
Bromine is more effective in hot water and across a wider pH range, making it the top choice for hot tubs and spas. It remains stable at higher temperatures and retains its sanitizing power longer. Chlorine is less effective at water temperatures above 80°F because it breaks down faster in hot water and only works effectively within a much narrower pH range.
pH Stability, Odour, and Skin Sensitivity
Many users find bromine has a milder odour and is gentler on skin and eyes, which is why it's favoured for spas. Chlorine often produces a stronger "chlorine smell" and can cause irritation for people with sensitive skin. In terms of pH stability, bromine works effectively across a broader range, whereas chlorine requires tighter pH control to maintain its effectiveness and prevent damage to hot tub equipment.
Alkalinity and pH
Alkalinity and pH are often mentioned together, but they serve different purposes in maintaining your hot tub's water balance:
- Alkalinity: This measures water's capacity to neutralize acids, acting as a buffer to maintain stable pH levels. It primarily consists of bicarbonates, carbonates, and occasionally hydroxides. The ideal range for total alkalinity in hot tubs is typically 80 to 120 parts per million (ppm).
- pH: This measures the acidity or alkalinity of your water on a scale from 0 to 14, with 7 being neutral. Hot tub water should be kept slightly alkaline, with a pH of 7.2 to 7.8. This range is close to the human body's natural pH, making it gentle on skin and eyes.