Since87: Exactly.
I've got a degree of EE and have some experience, and i see the terminology is the same
'impedance' used everywhere.
Murray:no one outside the USA knows what the hell is gpm or cfm... heck i don't even know exactly how long a foot is in meters. Every international project i've been on (not many, but a few already) involve only metric units...
As for doing unit conversions, it will be a hassle for me and a nest for future bugs. So currently it's a "NO", we'll see later. The program won't convert anything and will take raw numbers (or interpolated ones) as true values.
As for lpm vs lph: i don't care, as long as everyone is consistent with that. Pump mfgers and aquarium enthusiasts seem to like lph.