In this paper, we model the impact of networks on knowledge growth in an innovating industry. Specifically, we compare two mediums of knowledge exchange: random interaction, and the case in which interaction occurs on a fixed architecture. In a simulation study, we investigate how the medium of knowledge exchange contributes to knowledge growth under different scenarios related to the industry's innovative potential. We measure innovative potential by considering the extent to which knowledge can be codified, and the available technological opportunities. Our results tend to support the conjecture that spatial clustering generates higher long-run knowledge growth rates in industries characterized by highly tacit knowledge, while the opposite is true when the degree of codification is important.