I have looked at some of the threads on PVC plumbing but want to know what the benefit is over flexible hose. I have a 16' round ultra frame intex. Also, I went to my local pool store and they would not sell me a skimmer because I have an intex pool. What aftermarket skimmer is recommended for intex? Lastly I want to get a vacuum for the pool. I was floored by the prices at the pool store. Any suggestions?