Powerheads and head heights

[laka]

What is the significance of head heights? I note some powerheads have a large flow rate but the head height is less than other powerheads with a lower flow rate.
I want a powerhead for a spray bar on a 6ft long tank. Does that mean i should buy a powerhead with a larger head height as this will give me a better flow against the added resistance of the spray bar?
LAKA

 

[DarkSoul]

head height ios how far UP a tube of a given size, the pump will be able to push water.

So if you have a 6' head, and a long straight, 7' tube going stright up, the pump will not be able to push water out the end of the tube.

Head can be converted to PSI as well.... so considered head the "pressure" that the pump pushes with.