Abstract: An epicyclic mixing system for materials held in a tank is provided having dual concentric sun shafts which both orbit a pair of planetary drive shafts having mixing implements at their bottom ends and act to rotate the pair of planetary drive shafts about their own axes. The two concentric shafts are connected to dual drivers through separate drive systems so that the shafts can be selectively operated at different rotating speeds.Another epicyclic mixing system includes upper and lower housings driven about a central axis that extends through the upper housing by a sun drive shaft. The lower housing is adjustably secured to the upper housing. A first planetary drive shaft extends through the upper housing and a second planetary drive shaft extends through the lower housing. The first drive shaft is driven by a fixed sun gear about which the lower housing rotates so as to rotate the first drive shaft, which rotates the second drive shaft by way of a gear train.