Managing wastewater is a major logistical puzzle that impacts the environment, the climate, and public health. While metropolitan wastewater typically undergoes complex processing and sanitation, rural livestock wastewater is often simply composted for fertilizer, but composting can release harmful contaminants like ammonia, CO₂, and methane. One way to still capture the nutrients with fewer harmful byproducts is by cultivating microalgae, which actually absorb CO₂ via photosynthesis rather than producing it. But how do microalgae impact pathogens? A recent pilot study using raw piggery wastewater found that microalgae cultivation dramatically reduced the pathogen load while also triggering a dramatic shift in the overall bacterial community composition. Further investigation using the most abundant pathogen, Oligella, found that the microalgae weren’t impacting Oligella directly. Rather, microalgae cultivation reduced Oligella abundance through a network of other bacterial species. Microalgae cultivation also efficiently removed nutrients and improved the clarity of the wastewater. Larger-scale and longer-term studies are needed, but microalgae cultivation showed promise as a livestock wastewater management technique.