Summary: aqua balls are being birthed every second. To control the birth rate make sure the Emitter object is selected in the project pane then hit D on your keyboard to call up the dashboard. As you can see from this screen shot, 30 balls are being birthed every second. Dragging the 'Birth Rate' slider to the right increases the number of balls being birthed while dragging the
Image Dimensions: 313 x 218
Image originally found here.