Shae: the large opening is the main valve, while there should be a small opening/tube, where you attach the hose. On one hose there is also an adjustable valve and I believe I included a T valve. I found it worked best to have the large opening under water just below the surface to break the surface. The CTs are actually used to a full flow bubbler now xD they love it.
The light knob is in the back and should either be a press (firm) or a twist. Unless its the one in the side. So many tanks and different ways to turn on the light lol.
Glad to know everyone is doing well.