After a brief review on the use of spin wave resonance as a tool used to study the magnetic properties of liquid epitaxial garnet layers an example is given for CaGeSmLu:YIG films. A modified melt was used in which the Sm2O3concentration was reduced. The main result is that the growth kinetics produce film growth rate changes that influence the incorporation of Ca and Ge ions. This results in structured layers consisting of a transient and a bulk layer in which the anisotropy fields Ku/M are different. The change of Ku/M of the transient layer during film growth is interpreted in terms of a solid state diffusion process. The results of etch experiments are presented. Also values of the exchange constant A have been measured. Finally, growth conditions are estimated for homogeneous film growth.