Ex nihilo bug - (Agrarian Skies 3.0.1)
If you break a wooden barrel that has an item in it (i.e., dirt, clay), you lose that item.
Plus there's also the fluiduct rounding error (guessing that's what it is) giving more fluid out than in, but I see that's been mentioned sort of last month, and I get the feeling that's staying that way. (160mb for every 100mb) More testing reveals that it seems to be filling up the fluiducts until they reach max capacity of 900mb. So, a long line of say, 100 fluiducts is going to be 90,000 free mb of fluid. That explains why my 64 Magmatics seemed to always be full when draining from a portable tank.