Shashu grew very curious about water purification before it reaches our homes for consumption, after I told him that during our childhood, we used to drink rain water directly and that how I miss doing that now, due to the impurities present in air. Sea water is desalinated to remove salt and other unwanted minerals which are considered unfit for drinking and then in commercial purifiers, they are purified and made fit for consumption. Though rain water is stored, it can't be used for drinking directly but needs to be purified first and then only consumed .