Pseudomonas aeruginosa is an opportunistically pathogenic bacteria that causes fatal infections and epidemics in hospital environments. Due to the growing prevalence of antibiotic-resistant strains of P. aeruginosa, looking for alternative therapies is crucial. Bacteriophage therapy is emerging as a promising solution; however, it has not been approved for human clinical use and suffers from a lack of understanding of the complex dynamics between bacterial cells and phage virions. Mathematical models provide insight into these dynamics. Through a system of ordinary differential equations, we determined appropriate biological assumptions to effectively capture the complex dynamics observed between susceptible, infected, and mutated bacterial cells with bacteriophage virions in a microwell setting. Data fitting based on this model produced a set of parameter estimates unique to our experimental observations of a specific phage and P. aeruginosa strain. In translating observed optical density readings into bacterial concentrations, we also found that bacterial debris has a significant impact on optical density, with a lysed bacterium contributing roughly 40% as much to optical density readings as a living cell.