The increasing burden of domestic wastewater necessitates effective treatment methods to reduce Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Total Dissolved Solids (TDS) in sanitary sewage. This study explores Spirulina platensis, a cyanobacterium known for its high biomass productivity and bioremediation capabilities, in treating wastewater from septic tanks of a community sanitary block. Experimental setups consisting of photobioreactors were used for the phycoremediation of sanitary sewage at different dilutions of 25, 50, and 75% to maximize the removal efficiencies and the growth conditions for the microalgae. The results demonstrated significant and similar BOD, COD, and TDS reductions across all tested dilutions. However, 25% dilution resulted in the highest biomass yield of Spirulina platensis recovered to the extent of 2000 mg/l from the treatment units, highlighting its potential for economic recovery and reuse. This research underscores the dual benefits of using Spirulina platensis in wastewater treatment and biomass recovery, paving the way for further exploration in large-scale applications.