(๐ข) It should be clear and colourless.
(๐ข๐ข) It must not be foul-smelling.
(๐ข๐ข๐ข) It must have sufficient amount of oxygen dissolved in it.
(๐ข๐ฏ) It should be free from harmful microorganisms.
(๐ฏ) It must also be free from various chemical pollutants that are injurious to our health.