Defining a fluid in flow simulation so check volume can pick it up

Hi I am trying to define a fluid for a flow simulation. I have made unmerged parts and seperate parts and tried changing them to a fluid with the component control. everytime I do so and go into check geometry it gives me no fluid volume. I have made a couple incredibly simple parts to make sure I can do it and it still won't go. How do I define a fluid for a flow simulation? What am I doing wrong?

SolidworksFlow Simulation