The impurities in water can be classified in to 2 types.
1. Water soluble – Salt from earth and impurities from the decomposed bodies or organisms.
2. Non soluble – Soil, dust, germs, microorganism, moss and plants.
The impurities in the water will be cleansed by various natural methods. The following is a non-invasive water purifying technique that is told in Siddha system of medicine.
Clearing Nut (Strychnos potatorum):
This is the old and best method for decantation of water. Well filtered water is poured into a clean pot and 2 or 3 clearimg nuts are crushed and added with the water. The water is kept static for 5 to 6 hours. The minute impurities are settling down at the bottom of pot and leaving the upper level clear. Water also becomes sweet by this method.
Indian gooseberry (Phyllanthus emblica):
In this method of purification, well ripe fruits or woods of Phyllanthus emblica are used. In this method also, water becomes clean and pure, sour and sweet in taste due to Indian gooseberry.