Step 8: Shut-Off Valve Step 5
Use the waterproof adhesive to glue the whole shebang into the tupperware so the feed tube sticks out the bottom. You may have to bore out the feed tube so the hose fits snugly into it.
Also, you will want to fill in the secondary, smaller feed tube with adhesive otherwise the water will come out of there too, and probably fill your valve mechanism with dirt.
Voila! You have a miniaturized float shut off valve in a box, and you only had to cannibalize one toilet to make it.
Also, you are going to want to screw the adjustment screw all the way in so that as soon as that ball starts floating the valve will engage.