  We consider five-dimensional gravity coupled to a negative cosmological
constant and a single U(1) gauge field, including a general set of
four-derivative interactions. In this framework, we construct charged planar
AdS black hole solutions perturbatively and consider the thermal and
hydrodynamic properties of the plasma in the dual CFT. In particular, we
calculate the ratio of shear viscosity to entropy density and argue that the
violation of the KSS bound is enhanced in the presence of a chemical potential.
We also compute the electrical conductivity and comment on various conjectured
bounds related to this coefficient.
