I am thinking of buying a couple of small skids that have 50 gallon tanks and 100' of 3/8 hose. The person said both pumps were out but the tanks, reels [manual] and hoses were in good shape. He also said both hoses had couplers on the end and one had a JD9 gun that would go with it. He said one had a 1.8GPM shurflo pump and one had a 3.1 shurflo pump. For those of you that have electric sprayers what size pump is really needed for 100', [and I would like to add more hose], to spray the way it needs to spray? I was thinking at least a 5GPM pump for a chemlawn gun. Also would a trolling motor battery run one for a few hours?