It may be a simple question to you but I need help understanding head pressure and I need to set things up to ask it. Assume two 4 ft diameter by 25 ft tall water tanks, both are equally filled to 23 ft. Both tanks have chambers of the same diameter as the tank attached below them. Each chamber has a piston and has 2 ft of water above their pistons. Both chambers have a 4 inch diameter hose going from their chambers and into the tanks. On one of them, the other end of the hose penetrates the tank at 3 feet above the chamber. On the other the hose penetrates the tank at 22 ft above the chamber. My question is, which piston will require more force or is there any difference. I would also appreciate any explanation that you want to include.