Microbial metabolism drives global biogeochemical cycles through the decomposition of organic matter and assimilation of carbon (C), nitrogen (N), and phosphorus (P). These heterotrophic processes are mediated by environmental “ecoenzymes”, which are produced by microbes to break down organic matter and acquire nutrients and carbon for their metabolism. Ecoenzyme activities (EEAs) reflect the balance between the microbial demand for and environmental supply of nutrients. Comparing ratios of C-, N-, and P-acquiring EEAs provides inferences into the specific resources supporting microbial metabolism and growth. To date, EEA data collected from soils and sediments show a convergence towards 1:1:1 C:N:P ratios over 14 orders of magnitude in ecoenzyme rates, indicating a general equilibrium in C, N, P investment over broad scales. Relationships between C-, N-, and P-acquiring EEAs have only been quantified for planktonic and biofilm microbial communities across a limited number of studies, and are lacking for aquatic leaf litter. We have synthesized datasets of C-, N-, and P-acquiring EEAs from across the globe to include measurements from these unrepresented habitats, in addition to broadening the number of observations from soils and sediments. Through this unprecedented synthesis effort and application of ratio, vector, and threshold limitation analyses, we will assess patterns of ecoenzyme expression through the perspectives of both resource limitation and resource investment. Broadening the scope of EEA scaling relationships to multiple compartments found within flowing waters will provide new insights into coupled microbial metabolism and biogeochemical processing in streams and rivers. We also will identify if EEA equilibrium is a broad-scale generality for both aquatic and terrestrial ecosystems or if non-uniform scaling patterns point to key drivers of difference between habitats.