I modified the Lotka-Volterra (LV) competition equations by summing components for multiple species interactions. The model was field tested with three genera of cladocerans. The competition experiments were validated by monitoring free-swimming cladoceran concentrations and comparing the concentrations to those inside the enclosures. During a 32-day period, 11 replicates of all possible combinations of Alona, Bosmina, and Daphnia were run with different initial conditions in enclosures at Jasper Ridge Biological Preserve, adjacent to Stanford University in California. In all cases, Alona and Bosmina were able to suppress or competitively exclude Daphnia. Alona's numbers were significantly depressed when enclosed with Bosmina although there was no difference in Alona's numbers when enclosed with both Bosmina and Daphnia. When the effects of Alona and Bosmina were summed against Daphnia, phase plane diagram analysis showed classic Guassian competitive exclusion. This work demonstrated a new use of the LV equations.