I dose B-ionic parts 1 and 2 at 35ml/day in my 50g system. Dose is split, so each part gets 2 doses at 17.5ml/dose. They are dosed 1 hour apart. I find that dosing a larger amount at once leads to more accurate dosing by my dosing pump, because it minimizes the effect of backflow. In the past I needed to dose unequal amounts of part 1 and 2, but this was because my dosing pump, even though calibrated correctly, wasn't dosing precisely the same amount of each solution. This was due to uneven, slow backflow of the solutions between doses.