Board Thread:Questions and Answers/@comment-76.215.111.209-20121215184639/@comment-1863942-20121216140932

If Filters aren't pulling items from chests, then you do not have a valid destination for the items to go to. Because of the way tubes work, if the items can't go anywhere, they won't even leave the block they are in, whether it's a machine or a chest.

Since you're attempting to sort things using a filter, you need to color code tubes with a Paint Brush.