]]> Results for spring water showed a significant (P ≤ 0.05) difference in the carrying capacity for 10ppm compared to each treatment group. Carrying capacity followed Liebig’s law of the minimum and r-max Shelford’s law of tolerance. Lab-distilled water showed less growth and lower rmax values compared to spring water. The results showed that 50-100 ppm had a significantly higher (P ≤ 0.05) carrying capacity and r-max compared to 0 ppm. However, trends were not followed while using lab-distilled water. When comparing the controls of each solvent, it was found that lab-distilled water had a significantly lower carrying capacity compared to spring water and commercial-distilled water. It is most likely due to issues with the filtration system or plasticizers from the carboy. These results show the importance of determining phosphate concentrations required for optimal population growth and which concentrations have negative growth effects.]]>