Does a pressure tank need to be near the water fixtures?
only if you have a line that 400 feet away from your tank that is 1/4 of a inch. you will have two problems. one is that you use to much water for your pump to keep up with. second at a give presser your flow rate will be maxed out due to the size pipe you have. so if you have a 1/4 size pipe. you wont have any flow. because it will take alone time for water to flow. now if you really want some flow. put a 12 inch pipe to your buildings. still just having the one tank. but to be real for a second, just install a 1 inch line to the buildings. unless you have a 5 inch spout the one inch line will do you fine. to answer your question if your tank stays at the pressure 80 pounds. your only reason of no flow would be the pipe size. you want more flow. get a bigger pipe