I built the same system, but only used 3 nipples. I also used a drill bit a little too big - but I was happy that it dripped - the chickens quickly learned it had water, and how to get it. After a few weeks, it will not leak so much. Maybe a little sludge or calcium deposits or whatever gets into the leak, and now I only fill the bucket about every week and a half. So unless you're really peeved with it, just keep filling it and wait. (my bucket is 6 ft. high)
I also plan to get the push-in nipples soon, 'cause I want to make another bucket waterer. This time I'll build a little stand off the ground for the bucket and put the nipples directly into the bucket bottom. I'll still use the one with pipe, though. I think these nipples are a great idea - so much better than any other means of watering the chickens.
My mom lives with us - she's memory impaired. She's so cute - she always checks to see if the chickens have water. Every day she forgets that they get water from a pipe! She enjoys the chickens a lot.