NEED YOUR HELP. What are the pumps/equipments needed for an overhead tank? the water if from an underground cistern/water storage and should be pumped up to the tank then distributed below the end users. It's a 2 storey commercial building, 8 meters elevation above ground level. Tank is placed at the roof deck level (8 meters). I'm confused in how to distribute water with enough pressure (40-50psi). Your answers would be greatly appreciated. Thank you!