I water most of my 2.5 acres using irrigation water from gravity fed water tanks. I use a water pump to pump the water from the tanks into the delivery system. I have a pump controller relay working with the sprinkler control timers to turn the pump on and off. The problem is that once the pump is off, there is not enough pressure in the line to let the sprinkler valves shut off completely. The seep and continue to leak. I understand that a bit of pressure is needed to get the valves to fully close. Is the best way to do that with a pressure tank? Can I just use the pressure tank to maintain a little pressure in the system and still use the pump relay to turn the pump on and off? I water for a few hours each day, so would a small tank be enough to maintain pressure in the distribution line?