Moving water by reducing air pressure
Secure two small bottles. Fill single about half full of water and close it with a single-hole stopper carrying a length of glass tube that reaches nearly to the bottom of the bottle. Attach a short length of rubber tube which empties into the other bottle. Place these in the receiver jar and remove some of the air with the pump. What happens? How do you account for this ? If you wish, you may tint the water with ink.