In the Haber Process, we want to make as much as possible. We want the dynamic equilibrium to be such that a lot of [reactants/products] are formed. A(n) [de/in]crease in pressure will cause more products to form. We need as [low/high] a pressure as it is safe and economical to use. We say we need to use an pressure: the pressure for which we get a good yield for a reasonable price while still being safe. Pressures between 200 and 300 atmospheres are typically used in the Haber Process.