The white, milky appearance of hot water is due to the release of dissolved gases forming tiny air bubbles.
Understanding the Phenomenon
When you turn on the hot water tap, you might notice that the water appears white or cloudy. This isn't due to any impurities but rather a physical process involving dissolved gases. Here’s a breakdown:
- Dissolved Gases: Water, especially in main supply pipes, contains small amounts of dissolved air.
- Pressure Release: When the hot water tap is opened, the water's pressure suddenly decreases. This lower pressure allows the dissolved gases to come out of the solution.
- Bubble Formation: As the gases escape, they form millions of minuscule air bubbles. These bubbles are so small and numerous that they scatter light, making the water appear white or milky.
- Pipe Issues: Sometimes, a tear or damage in the water pipes can cause extra air to be drawn into the system, which can further intensify this milky appearance, according to the reference.
Practical Implications
The white water phenomenon is usually harmless. The bubbles typically dissipate within a few seconds, and the water returns to its usual clear state. This makes the temporary milky appearance not an indication of contamination or water quality issues. Here are some observations:
- Appearance: The water might look cloudy or milky when initially released.
- Duration: The cloudiness is usually temporary and disappears quickly.
- Harmlessness: The phenomenon is generally not a cause for concern regarding water safety.
- Cause: The primary cause is dissolved air, not added substances or impurities.
Is There a Difference Between Hot and Cold?
While both hot and cold water can have dissolved gases, the effect is often more pronounced in hot water. This is due to the reduced capacity of hot water to hold gases, which causes more gas to be expelled when the tap is opened.
Summary of Causes
| Cause | Description |
|---|---|
| Dissolved Gases | Water naturally contains dissolved air. |
| Pressure Release | Opening the tap reduces pressure, causing gases to come out of the solution. |
| Bubble Formation | Escaping gases form many tiny air bubbles, scattering light and creating a white appearance. |
| Pipe Damage (Possible) | A tear in the pipe may introduce additional air, further enhancing the milky appearance. |
