Oct 29, 2009· Say I make a suction dredge nozzle with a pressure washer hose at 2500 psi inlet to a 3" intake nozzle at degrees. Depth of water 6'. so say 3 psi...that's 2497 psi differential. Will the drop in pressure, and the resultant vacuum (venturi effect) work better than say, a larger quantity of water from a 2 " inlet from a Honda hp pump at 200 psi?