Trying to vacuum for first time. I hear main drain needs to be turned off. None of mine were labeled. I have 3 handles. 1 handle controls which returns water comes out of (spa vs pool). Another controls something with the skimmer. If turned one way, the pool doesnt seem to spill over well. The other side, it does. The last one I never touch but it is a prelead to the previous one mentioned that has some control over spill over. Any suggestions on what this setup is and how to maximize it for vacuuming? The reader mine came with (if it still works) doesnt move but there is suction in the skimmer. I have the adapter seperating the skimmer plate and the rest of the hoses. I believe blue nozzle set on MAX.