Quote Originally Posted by desertstalker View Post
See http://www.lerc.nasa.gov/WWW/K-12/Wi..._pressure.html

The Pressure of a fluid is determined by density and depth, the volume has nothing to do with it.

This is because a fluid exerts pressure equally in all directions.

Or are you going to make be dig up my Fluid Mechanics notes to find the derivation for the formula : P = Pa + roe*g*h (notice the absence of any dimension other than height)

I believe you may be confusing force and pressure.
Isn't pressure just the amount of force per unit area?

I think what people are trying to explain here is the potential energy contained in the column of water due the the gravity effecting it and its weight, so the thinking is big volume is more energy down.

I don't think this will stand true as it is a closed loop. No water is able to go down until it returns to the res. (finger on straw = lift from drink) 1 cc of water pumped in to the res = 1cc allowed out of the res. The res water will be "held up" with surface tension, ie defeating gravity.

I think there will be a point where it all gets messy with large enough and long enough res's that enable the surface tension not to be strong enough.

For all intents and purposes though, res volume works as a buffer for temps and not much else. Correct me if I'm wrong here. I'm getting old and rusty.