eprinex = ivermectin. this kills roundworms. just about the only thing piperazine (wazine) kills is roundworms. Ivermectin kills roundworms + just about every other worm +mites too. It doesn't get tapeworms though. Piperazine can be given by mouth. In the water directions are more for people with large flocks. If you have a small flock, you can give it to each bird individually- just weigh them and dose them by weight. SO- if you are giving eprinex, you don't need wazine later. Some people give wazine first as a 'gentler' dewormer, then give ivermectin.