Many exciting "anomalies" affecting long-time and low-frequency phenomena in the photoactive halide perovskites that are presently in the focus of the field of photovoltaics turn out to be rather expected from the point of view of solid-state ionics. This Perspective discusses such issues based on the mixed conducting nature of these materials and indicates how the solid-state ionics toolbox can be used to condition and potentially improve these solids. In addition to equilibrium bulk properties, interfacial effects and light effects on the mixed conductivity are considered.