[Buckeye Field Supply]

Assuming that your red arrows on the housing lids indicate which one says "in" and which one says "out":

First (left most) housing should contain a sediment filter
Middle housing should be another sediment or a carbon block
Third housing (right most) should be empty or have a carbon block

Tap water comes in to 2 and comes out 8.
Connect 8 to 3 on the RO membrane housing.
Connect 7 on the RO membrane housing to 4 on the DI housing
Rotate the DI housing so 9 is at "12 o'clock" position rather than "4 o'clock."
Water coming out of 9 will be your final DI water for use in your tank.
Remove the top, white "taste and odor filter" from your system. It does more harm than good in this position.
Connect 6 to the un-numbered port on the black-handled flow restrictor.
Connect 1 on the flow restrictor to a drain.

Russ