Capacitive deionization (CDI) has recently gained some degree of popularity as a water treatment technology. This paper demonstrates the benefits of coating low surface area carbon electrodes with a sub-micron nanoporous layer of either gamma-Al2O3 or SiO2. As shown by cyclic voltammetry, the oxide layer, having pores sizes ranging from larger micro to meso, substantially increased capacitance for ion removal while still maintaining reasonably high ohmic conductivity. The amount of Ca2+ removed in a CDI cell comprised of a SiO2 coated carbon as the negative and gamma-Al2O3 carbon as the positive electrode was nearly five times higher than a cell with uncoated electrodes. Removal of Ca2+ followed pseudo first order kinetics, while Cl- removal was better described by a first order kinetic equation. The highest value for Ca2+ adsorption measured was 0.17 mEq/g of electrode material. This compares favorably with previously reported literature values obtained with high surface area carbons. The removal of Ca2+ and Cl- proved to be asymmetric (mEq Ca2+ > mEq Cl- removed). Consequently, to maintain electroneutrality, pH decreased during the removal process. Furthermore, some of the asymmetry was found to be due to a parasitic reaction, that of Cl- ions being oxidized to ClO3-. (C) 2013 The Electrochemical Society. All rights reserved.