Here's a view at an angle from the front.
I will post a diagram later, depending on how many people request it.
1 Lee's medium specimin container (intake)
1 Lee's Large specimin container (rear)
1 U-Tube (for siphon action)
1 scrap pice of plexi (to hold the intake box)
1 acrylic bolt/wingnut (to attach the intake box to the piece of plexi)
1 PVC 1" male adapter
1 PVC 1" female adapter
1 rubber gasket to fit under the rear box through PVC
Dremel (play dentist and cut them teeth)
Acrylic glue (any strong bonding acrylic adhesive)
Take the smaller of the containers and dremel off the overhang arm. Then play dentist and cut some teeth out of the front and sides. You will also want to drill a hole in the back near the top center of the container (just big enough for the acrylic bolt to fit through).
Drill/dremel a hole at the bottom of the larger container to fit the PVC piping (instant bulkhead) and install the PVC/gasket.
Take the piece of plexi (wide as the smallest part of the overhanging portion and as tall as the intake box), and glue it to the small portion of the overhang of the rear box (larger container). Then using the dremel, cut out a strip from the bottom of the plexi to the desired maximum height of the intake box. You want this gap to be as wide as the acrylic bolt so you can slide the intake box up and down.
After removing this strip, you should be able to connect the intake box to the rear box using the acrylic bolt.
Throw it in your tank! place the U-Tube in there and siphon out the air. Adjust the height of the water by sliding the intake box up and down the grove you cut into the plexi.
Closup of the intake box. The wingnut is holding the intake box in place.