Do everything else as for the first variation. If the pressure in the upper hose is too high, place it in a piece of pipe (I used the pipe with the in...
I will show you how to make a very simple but effective venturi vacuum pump out of cheep laboratory material. You will need several minutes to make it. The principle of this pump is that when the water flows through the vertical tube, the vacuum is generated at the horizontal tube.This type of pump is widely used in chemistry labs for many purposes as filtrating under reduced pressure for example.
Step 1: Material
In this case I have used an 1.5 mL eppendorf tube and 3 pipette tips of 1 mL. You can use any sort of pipes as long as you follow the rule from the drawing (intro). To glue the parts I used a glue gun and to attach the pump to the faucet, I used the plastic hose that can fit to the pipette tips and a piece of a bicycle tube.