tank and pump

Hi there,

I have a car-wash business and sometimes I experience the water shortage problem(low pressure), so, I am considering the installation of tank and pump to cover the peak time usage. can anyone tell me what kind of tank and pump needed? do I need normal atmospheric tank? or prssure rated tank? how about pump? what kind of pump? how about operation? if business is slow, in order to save electricity, can I just use normal city water(pressure) and only kick-off pump during peak time? how does it configured and operated? thanks