[Ron_r1959]

I run an electric in-line pump on my 41 that is 4-5 psi and the mechanical is 2-3, it doesn't cause and issues really. I use it mostly to prime the system after its sit for awhile. Just keep in mind most electric pumps work best close to the tank, they are made to push mostly. If you put a inline filter in, put it after the mechanical pump. If you are all ate up about keeping the pressure down you can put a pressure regulator after the main pump if you want.