@Xeorm, thanks for the link - I get the idea. I guess I was confused because thinking about it, the physics of the storage tank should increase pressure as the contents increase, but I guess it isn't implemented that way (or my mental model of this is off)

The numbers? Not sure I follow; is there a good solution?

I had assumed storage tanks abide by the same rules as pipes (high pressure -> low pressure); is this not the case for storage tanks? For example, part of my setup looks like: http://i.imgur.com/Fgh2jrJ.png

Tank1: 22.5k
Tank2: 21k
Tank3: 19k
Tank4: 17.5k
Tank5: 16k
Tank6: 14k
...
Tank14: 3k
Tank15 ...