  We are conducting a large spectroscopic survey of over 130 Southern ZZ Cetis
with the Goodman Spectrograph on the SOAR Telescope. Because it employs a
single instrument with high UV throughput, this survey will both improve the
signal-to-noise of the sample of SDSS ZZ Cetis and provide a uniform dataset
for model comparison. We are paying special attention to systematics in the
spectral fitting and quantify three of those systematics here. We show that
relative positions in the $\log{g}$-$T_{\rm eff}$ plane are consistent for
these three systematics.
