need help on transplanting

ok, so i believe my yield is being effected by my transplanting technique, so i am working on improving it. My current soil is 2:1 of Pro-Mix BX to Foxfarm Ocean Forest soil with extra perlite. Once I get my seedlings to pop up from there rapid rooters I place them in 16oz cups. I let them grow in there for a few weeks then transfer them to 1 gallon square containers. I vegg them, train them ,fim them for a few more weeks then I transfer them to five gallon containers. The issue I am having is it seems when they go from 1 gallon to 5 gallon containers the 2:1 ratio gets screwed up. I re-use the soil from the 1 gallon containers then start fresh with new soil to fill the rest of the 5 gallons up. What am i doing wrong
? do I need to switch my soil??

Maybe it is that I hit the pipe once too often this morning, but in what way do you see your yield being affected? Do your plants show signs of unhappiness when they go to the 5 gallon, change shades or become more stunted? I haven't ever used your soil mix, I make my own so don't know what you might be lacking. I am interested in knowing what you think is wrong in the plant then we can figure out the best solution.
You have a very simple ratio to carry up to your bigger containers. Maybe just try to find the space to mix a larger amount of soil so that it is the same batch all the way through the grow. I find it much better on the plants now that I mix a years worth of soil at the same time, never any change in their soil that way. Feel free to PM if I can help.

Wait until its rootbound, if the rootball is disturbed or crumbles it stresses the plant .