tank phisics and measures? metric units please

Hello,

I would like to learn and understand more or less the measures and
phisics of the tanks.

Please in metric units.

Is it possible approximatelly to calculate the weight of and empty
tank given its material steel or aluminium and its measures lenght and
diameter( of course generalizing if possible on the alloy grade used,
to know the specific weight or steel or aluminium )

What will be the calculation to get the empty tank weight ?

How much more or less weight the tank valve?

Given the capacity of the tank is it possible to calculate the weight
of the compressed air insde it ?

I will also depend on the depth ?

Please can you give me the formula to calculate the weight of the air
inside a tank depending on the depth and pressure inside the tank,
measured at the console pressure gauge. Or given the pressure , depth
is not necesary to be taken in consideration ?

I am not sure if air density depends on depth and temperature of the
water. Please take in consideration all the necessary parameters to
calculate the air weight inside a tank given the air pressure read at
the pressure gauge and tank capacity.

Thanks,

Mario