This study aimed to evaluate the effect of vegetable type and processing method on the population growth of infusoria species. To compare the suitability of different substrates for raising infusoria, a two-factor experiment was designed using 10-L plastic jars, each containing 8L of river water and 100g of vegetables (lettuce or cabbage) that had undergone different processing methods (chopped, unchopped, ground), corresponding to 6 treatments. Infusoria were first observed on day 3 of the experiment. There was an interaction of vegetables and vegetable processing method that had a very clear effect on population growth: processed vegetables tended to support higher population densities than unprocessed vegetables. Population density reached a maximum of 1,816 ind./mL with ground lettuce, while culture with ground cabbage yielded a maximum of 1,165 ind./mL. Euplotes sp. accounted for around 80% of the population composition of infusoria for both vegetables.