Is rainwater better for plants than tap water? Untreated, it has the advantage of being free of limescale, unlike tap water. Its pH is slightly acidic, but it is rich in nutrients necessary for plant survival.
The temperature of the rain, close to the ambient climate, helps to avoid a possible thermal shock to the roots which receive it during watering. In fact, it is advisable not to use rainwater too frequently if your home is in a coastal area. According to a study conducted by scientists at Stockholm University, rainwater on earth is unfit for consumption.