In the discussion about calculating pressure in a cylindrical tank, the formula P = P_a + pgh is highlighted, where P_a is atmospheric pressure, p is the density of water, g is the acceleration due to gravity, and h is the height of water above the point of measurement. The user is attempting to find the absolute pressure 6 meters above the bottom of a 20-meter tall tank filled with water, questioning the value of g, which is indeed the gravitational constant typically approximated as 9.81 m/s². The conversation emphasizes the need to determine the pressure exerted by the water column above the measurement point. It is clarified that the measurement point is 14 meters below the water surface, which affects the pressure calculation. Understanding these factors is crucial for accurately determining the absolute pressure at the specified height.