I was clearing the landscaping behind my pool when I came across a flexible PVC pipe w/an open end. I did an exploration dig to see if it was just left over from when the pool was developed. The flexible PVC is attached to a 1 ½ hard PVC. I stopped digging at this point. I purchased the house 3 years ago and have never used, nor knew about this hose. Does anyone know what this hose is used for?