I have a slide I have added to our pool, I’ve just been hooking up the hose to it to run it for my kids. Obviously it adds water to the pool so I have to watch the levels and drain when I need to keep it but it is also diluting little by little. There is PVC coming out where the equipment is. It has a valve on it. I have no idea what it is for. Maybe it was there for another accessory at one point? I have opened it up and played with it and no water is coming out of it. On floor four but obviously, therefore something right? I also have all the original paperwork for the can’t find that it was put there for something. I have attached two pictures showing where the pipe is.