One of our users' favourite features is being able to use container apparatus with liquids!

Here's how to do it:

1. Add an apparatus that contains a liquid

2. Select the Fluid Tool. You can also press "2" on your keyboard
   
3. Click on the liquid to change its colour
   4. Drag to change the amount
   

Note you can rotate the apparatus and the liquid will rotate itself correctly. Remember to switch back to the Select Tool first, or pressing "1" on your keyboard.