Cyanobacteria is growing rapidly throughout the world releasing various toxins leading to the deaths of marine life at an alarming rate. The purpose of the study was to test the effects of phosphate concentrations on cyanobacteria to find the optimal conditions that cyanobacteria bloom in as well as conditions where the cyanobacteria die. The hypothesis was that when phosphate concentrations increase in a liquid medium with Cyanobacteria present then the biomass and blooming rate of Cyanobacteria will decrease. In the current study, the researcher created four variant concentrations of phosphate to record the growth of the cyanobacteria. The researcher used the following cyanobacteria: Anabaena, Tolypothrix Distorta and Fischerella. To record growth of cyanobacteria, the researcher measured the amount of light absorbed by the cyanobacteria in a spectrometer. The researcher tested the hypothesis over a three-day period measuring the various absorbance rates. The Anabaena grew the least out of all the cyanobacteria and the most effective concentration was 30 micrograms/liter. Tolypothrix grew the second most out of the various bacteria and the concentrations it grew the most in was the 20 micrograms/liter phosphate concentrations. Fischerella grew the least out of the three cyanobacteria species that were tested. The concentration that it thrived and grew the most in was the 30 micrograms/liter solution. The researcher concluded that the optimal conditions for cyanobacteria are for Tolypothrix Distorta is 20 micrograms/liter and dies at any concentration above that. In contrast, Anabaena and Fischerella optimal concentration is 30 micrograms/liter. The findings of this study can effectively control Cyanobacteria growth over time and preserve the current ecosystem