About to make my first PVC feeder. I have looked all over this site at other peoples setups. Most use either a 90deg or (2)45deg pieces at the bottom of the fill tube. My concern is that the food will not spread the length of the feed area at the bottom by gravity alone. How is this achieved? Right now my birds are still eating mash. Do crumbles make a difference? I can switch next time I get food. They are still on grower at this point. Input? Thanks!