Sorry if this is a dumb question. I just bought my first house a couple of months ago and I was lucky enough to get an above ground pool with it. I have looked up a lot of different filtration setups today and haven't been able to figure out what one of the hoses I have is. A house comes out from the skimmer then it splits. One end goes into the pump which I understand but the other end seems to have a valve and go into the ground. I turned the valve and water ran into the filter (haven't turned it on yet I'm still filling the pool). I'm not sure how deep into the ground it goes or what the point of the hose is. Any help with this would be greatly appreciated.