Calculating Water Flow: Time to Fill Canister

[Red Dog]

I have been trying to work out a formula to calculate how long it might take to fill a container of a known capacity in various depths of fresh water. The container would have a foot valve for entry and a pipe extending above the surface for air displacement. Tests at 1metre deep have given about 3.5 litres per second for a 40mm and 50mm foot valve and an air pipe of 13mm and 20mm.
I have a formula for working out the pressure at a set depth and I am assuming that it should fill more quickly the deeper it is.
Will the length and/or the diameter of the air line affect the time it takes for the air to evacuate?
If I pump the water using compressed air, would the advantage of the extra water over the canister be negated by the extra head to pump?
I would like to input values for canister volume, foot valve size, depth and air line diameter and obtain the time it will take to fill.

Thanks

 

[Chestermiller]

If the air line had zero diameter or an infinite length, do you think this would have an effect?