When I float test, after about 7-8 minutes I will take a big spoon and scoop off the ones that are still floating and put them in a smaller bowl so they can continue to float longer.
At 10 minutes I have all of the sinkers and put them in a strainer and rinse them off good.
I end up with a small bowl that still has the floaters left in it.
I will let them float a little longer, and at 15 minutes several more of those will sink, and I pick them out, rinse them and put them in the good pile.
This pic below was at about the 12 minute mark.
There were just over 50 seeds still floating at that point.
Thats 50 out of approx 14,000-15,000 seeds (he sent me a bit more than 2 pounds).
At the 15 minute mark 3-4 more of those had sunk and I rinsed them off and put them in the good pile.
Tossed the few that remained.
TNhunter