The plumbing in our house has never been quite right. The toilet in our master bath started flushing really slow a month or so ago. It's been plunged, but I'm not sure it's a clog issue. It need replaced as is, so I'm going to do that, but wondering if I shouldn't put a new supply line on (hard water), snake the line, and maybe check the roof vent? Anyone have this issue before that can think of any other troubleshooting tips?