I have my Foundry set with the pick up nearly downward; I draw off to the fermenter and it initially has a bit of trub then runs clear until I get near to the bottom of draining off the last of the wort, at which point I stop (I am trying to get to the point just before it sucks up the bulk of the trub). I leave maybe a cup to a cup and a half of wort and trub behind. If I miss it and collect more trub than expected, I don't really sweat it. My beers are brilliantly clear, but I use Brew Tan B, also, split between the mash strike water and at the end of boil.