Zirconium cobalt (ZrCo) is being evaluated as an alternative to uranium for tritium storage. The pumping speed and pressure-composition-temperature isotherm profiles for the ZrCo hydrogen and tritium systems were measured to determine isotopic differences and the effect of He-3 induced aging on ZrCo performance. Hydrogen is pumped by ZrCo at a slightly faster rate than tritium under identical test conditions. The ZrCo/H2 system has a slightly lower equilibrium pressure compared to the ZrCo/T2 system at corresponding compositions. Aging ZrCo with tritium for 57 days appears to have no noticeable effect on the tritium pumping speed relative to virgin ZrCo.