Rainwater is naturally soft. This is because it forms through the process of evaporation and condensation, leaving behind minerals and salts that contribute to hardness in other water sources. As rainwater falls, it is typically slightly acidic due to dissolved carbon dioxide gas from the atmosphere.
However, as rainwater soaks into the ground and flows through soil and rocks, it picks up minerals like calcium and magnesium, which contribute to water hardness. This is why river water and groundwater are often harder than rainwater.
Here's a summary of the key points:
- Rainwater is soft: It lacks the minerals that cause hardness in other water sources.
- Rainwater is slightly acidic: This is due to dissolved carbon dioxide gas.
- Hardness develops as rainwater interacts with the ground: Minerals like calcium and magnesium are picked up, making the water harder.
