A method of determining a particle size distribution in a wellbore fluid including collecting a volume of mud from a vibratory separator, sampling a volume of the collected mud, and testing the volume of collected mud with a test kit to determine the concentration of a sized additive in the mud is disclosed. A system for determining particle size distribution of a fluid, the system including a vibratory separator, a meter configured to receive a separated material from the vibratory separator, a counter configured to count the number of loads collected by the meter, a test kit including a sieve and a measuring tube, and a centrifuged configured to receive the measuring tube is also disclosed.