How to Make a Gravity Bio-Water Filter - Cheap and Easy

2" PVC
3/4" PVC
1 Interior and exterior threaded 90deg angle
1 exterior threaded, smooth interior 90deg angle
2x2" sleeves
2x2"-3/4" interior threaded adapter
1 male to male threaded PVC
1 male to female hose adapter
1 5 gallon water jug with 3/4" threaded cap
screen
separate out 3 or more sizes of rocks and pebbles - free
sand - free