Steve,
I too think it's the Viscosity you are using, all the other values in your equation looked correct to me. I think its' a Kg vs g discrepancy. For reference, here is the online calculator and equations I was using.
Absolute, Dynamic and Kinematic Viscosity
It yields exactly 1000 times greater Reynolds number than you calculated.
As for the low power requirement I calculated. I don't know, that's what prompted me to start digging into the equations. I felt that the pumping power that I calculated seemed low, hence the request for someone to chime in. (Thanks again, btw) I believe the pipe friction loss tables supplied by the pipe mnf already take into consideration laminar/turbulent. They are just head loss vs gpm irregardless of what's going on in the pipe, so ft of head * lbs of water moved during a particular time period should give ft-lbs/time.
Len