plumbing good?

[Dan F]

I would get rid of all of the elbows as they reduce flow (by quite a lot... sometimes up to 1 foot of head pressure!) and give more points for unnecessary leakage. Just go straight from the pump to the valve to the tank. Then I would go straight from the tank to the valve to the sump.

Elbows (or any restriction, for that matter) won't change head pressure, only flow rate.