A number of facilities have been either constructed or are operating to extract tritium from the heavy water moderator systems of nuclear reactors. However it is expected that most fusion reactor concepts would require the recovery of tritium from light water coolant or blanket systems. This paper highlights the significant differences between recovery of tritium from H2O and D2O in terms of feasibility, equipment size, process power requirements, tritium inventory etc. Process options are compared on an equal basis and quantitative differences for some typical fusion type of applications are highlighted. It is shown that distillation processes are especially more powerful for H/T systems than for D/T systems.