While it is often suggested that moderate-scale ad hoc sensor networks are a promising approach to solving real-world problems, most evaluations of sensor network protocols have focused on simulation, rather than real-world, experiments. In addition, most experimental results have been obtained in limited scale. This paper describes a practical application of moderate-scale ad hoc sensor networks. We explore several techniques for reducing packet loss, including quality-based routing and passive acknowledgment, and present an empirical evaluation of the effect of these techniques on packet loss and data freshness.