If you have a small submersible pump similar to the one I have, it may not put out enough pressure to do what you want. I built an emergency water supply in our basement after the hurricane destroyed our city water system. I have two 55 gallon food grade barrels in the basement, full of clean well water from a generous neighbor up the road. I closed the valve where the city water comes in and hooked a hose from the submersible pump in a barrel to a boiler drain spigot in the basement, via a hose to backfeed our plumbing so we would have water from the tap. It works barely well enough to take a shower....but it does work. Very low water pressure even after bleeding the air from the lines. Play around with your pump in a 5 gallon bucket of water to see how it does before you invest in a big tank. That way you can work the bugs out before spending a lot of money on a tank.