The growth rates of ciliates estimated under natural conditions with the widely used size fractionation method are much lower than those observed in cultures. However, recent studies performed with a modified dilution method demonstrated that the size fractionation method underestimates the ciliate growth, because it does not remove predators of the same size as the organisms studied. Thus, it is still unresolved whether ciliates are food-limited in different systems and whether their growth rates are indeed lower than those in cultures. This study was conducted in highly eutrophic Lake Gardno using a modified dilution method. Each time, two dilution experiments were performed (around noon and around midnight). Four small, common ciliates from the genera