Why don't wi use water instead of mercury in Toricelli experiment ? If we are ready to do this experiment, what length tube is needed ?

Explanation

We cannot use water instead of mercury in Toricilli experiment because, if we want to use water, we have to take the glass tube of length above 10 m, which is inconvenient.
If water is taken,
`P_(@)=rhohg`
`1.01xx10^(5)=10^(3)xxhxx9.8rArrh=(1.01xx10^(5))/(10^(3)xx9.8)=0.1030xx10^(2)=10.3m`