Cultivation of benthic algae promises efficient and sustainable water pollution remediation and biomass production. However, process yields at the large scale in open systems can be limited by competitive exclusion of desired species by wild cultivars. Process control over recruitment, colonization, and growth of desired cultivars is necessary. Emulating the physical characteristics of colonized substrata using new approaches promises to advance process control via species management in mixed periphytic communities. This preliminary work explores the premise that control over substratum characteristics can result in control over the structural and functional characteristics of the colonizing algal biofilm community. In this work, bare and colonized natural surface specimens are collected from rivers, and their surface topography measured for insights. 3D printing is used to manufacture growth plates for colonization in streams. The results show that at least two species (Microspora Willeana and Stigeoclonium tenue) show preferences for attachment and colonization of specific surface topographies.