Lynne, you raise an interesting point...it is my understanding also that lilies don't like constantly running or splashing water...however, I don't run my pond 24/7, which a lot of people believe is essential for the sake of their fish...I only run it a couple of hours a day, even in the heat of summer...I have ten fish (including three koi) and (knock on wood) have not lost any fish in six years due to oxygen deprivation (raccoons and herons are another story)...I do have four separate waterfalls, one of which creates a lot of splash so perhaps the two hours of the four falls create more oxygen bubbles than one non-splash falls does over several hours...I don't know the answer but, in any case, the fish and plants appear happy.