How much water does a fish actually need to survive? And how long can they survive on the bare minimum?

Question

I saw a person selling goldfish in this hot summer in New Delhi, and it got me intrigued about fish and marine life, like can they see the water they are living in? If I take them out of the water and keep splashing water on them will they survive?

In: 34

Answer 1

1 gallon of water per inch of fish

Or 3.8L per 2.5cm for metric users.

Thats what i was told is a rough rule of thumb by the guy at my local fish store