i have been makeing 100l batches of biodiesel for about 6 months now i use 20l of methonal do a titration test and usuly need about 750g of costic soda and 100l of used oil mostly rapeseed but when done and i drane off the glyserine an i am only left with 85 - 90 L of fuel so how come i am not gettind the full 100L