India, Jan. 26 -- A British biologist has sparked a discussion online after sharing a video in which he tests water from the river Ganga and explains the results. The video was shared on Instagram by Jeremy Wade, a British television presenter, author and biologist, who is widely known for the show 'River Monsters'.

In the clip, Wade demonstrates a simple water test using a container primed with chemicals that change colour in the presence of contaminants. "Pink means the river is clean. Anything else spells trouble," he explains, before testing mineral water for comparison. The mineral water turns a darker pinkish-brown shade, which Wade describes as how clean water should appear.

He then tests water taken from the Ganga River. The sam...