Don't try to ADJUST the bps of diy, it will never be consistent. As for gettin it into the tank, your bottle has to be tipped or tube too long. I make it so that the bottle is filled 1/2 -2/3 and then the tube only extends to the bottom of the cap. No need for more. There is no way for it to magically jump through the air into the hose, so it had to tip at some point.
EDIT, i see what you are saying. Ditch the gang valve. It is completely pointless to try to regulate diy, as it changes constantly.