Opinions please! Forget about head loss for the moment and please help me understand this. I have a Sicce Syncra SDC 7.0 return pump which is a DC adjustable pump with an advertised flow range of 800-1900 GPH. If I run this pump at 50%, am I running 950 GPH (1900 highest speed x 50%), or am I running 550 GPH (1900 highest speed minus 800 lowest speed = 1100 x 50%). If it's the first one, then that would be higher than the advertised lowest GPH. Anyone??