Take your smallest plate and lay it full a sample of the seeds.  Watch how they fit and how they drop out of the meter.  It takes some time but worth it.

I apply just enough vacuum to hold the seed in the plate a full revolution.  You can hear the seed click through the meter without the fan roaring.  It may be worth buying new discs, the last I bought was $22 and that has been awhile, probably double now.  The 3D printers will print a new disc if you have one pattern.

50 lb seed planted better for me and liked at least 42 lb seed on my planter.  Flats have a little more yield but yes rounds run through that system so smoothly.

http://talk.newagtalk.com/forums/thread-view.asp?tid=487&mid=2170#M2170

http://talk.newagtalk.com/forums/thread-view.asp?tid=50484&mid=356566#M356566

Ed