The simultaneous growth of LPE films on two-inch diameter Gd3Ga5O12substrates with nominal film compositions in the (YLuSmCa)3(FeGe)5O12system is studied. The effective distribution coefficients of Ca2+-Ge4+, Y3+, Lu3+and Sm3+are discussed and related to the magnetic property variations observed as a function of film growth rate. The approaches for material property control are evaluated and examples given of expected property variation within a stack of epi wafers grown under constant thickness or constant growth rate conditions. A design is shown for a 18 at-a-time and a 30 at-a-time growth holder. Data is presented to indicate the radial thickness uniformity, thickness, saturation magnetization, collapse field and anisotropy field variation typically observed in multiple substrate film growth. A technique for minimizing flux caused mesa formation is evaluated. with comparative data showing the effectiveness of this technique.