A year ago I moved into an home with an inground pool. Everything was working great until recently I noticed that my vacuum wasn't picking up the leaves that were sitting in the bottom. So I inspected it and found that there is very little suction from the port that the vacuum hose is connected too. I have a sand filter and I've tried backwashing it. I've made sure that the hose and vacuum aren't clogged. I'm not sure what else to do. Any advice is appreciated.