I bought this system off craigslist and understand everything except one or two pipes. The red circle on the left, is where I cut the pipe off. I attached a pic of what I cut off. Not sure where it went or what its purpose was. The red circle on the right with the jandy valve, I assume is a backflush? There is a water spigot not shown (the fileter is hiding it). Also, those are dual salt cells on the left coming from the heater discharge. With is plumbed that way, I need to make sure that I'm not over chlorinating the spa right? If I keep it turned on when the spa spillway is on, will it still over chlorinate the spa or is that okay to do?