Sean, Nice artwork !

This is similar to mine, but i do use the Bunnings bag - (basically a water tank screen on top to catch the crunchies), then into the woolies bag - i usually stop pouring from the drums when the thick white oil shows up.

I can put about 40 litres into a Bunnings bag then head off to work and most of the time it has filtered through by the time i get through.

I actually have 2 x 220 litre poly drums - it takes roughly 1 week to fill one and then i let it settle for another week. I have a drain at the bottom and drain off about 10 litres of crap.

(My house is on a sloping block so i let gravity do the next part for me but your pump could do the same), i have an outlet about 6 inches from the bottom of the poly drums connected to 13mm poly irrigation pipe.

It runs down through here into the bottom of another 220l poly drum and upflows to the top and then into a 44Gallon drum with 3 x 5 micron filters in the top

I get about 600 litres through a 5 micron bag filter before they start to slow down - so the upflow seems to work well.

You might want some form of bypass for the 5 micron bag in case it backs up and overflows ? Maybe clamp it around 6 inch PVC pipe (hose clamps) then have an outlet towards the top of the PVC pipe that goes back to your settling tank

Craig