Soil pores are elusive, as their dependence on the surrounding soils for size and shape makes them difficult to measure and classify. At the same time, they have a rhyme and rhythm, reflected in a perpetual relationship to the particle or aggregate size and to the conductivity of water through soil. If soil pore size (diameter, circumference or surface area) is determined from soil particles and processes, how do they possess a statistical relationship in a large variety of soils that is universal? This investigation begins with a relationship between aggregate size and pore size (2:1) over a range of soil pore diameter from 0.001mm to 10 mm (105). Hydrology equations that applied a soil permeability function characterized by the soil pore diameter to compute hydraulic conductivity, were applied to the range of pore diameter, assuming vertical gravity drainage. The results supported the earliest hydrology functions where hydraulic conductivity (K) varies proportionately with the 4th power of the radius of a tube. Thus, the range of K equations varied with the pore diameter squared, dependent on the range where the specific constants were applicable, and on the addition of variables such as specific surface area and void ratio. The most accurate equation in estimating K from soil measurements may depend on the specific wetness and soil characteristics. An interesting result of this study is to understand why this very simple relationship exists, when it ceases to exist, and where it is applicable in modelling.