I have a very old pump (I just moved to this house) and I was thinking to get Pentair Intelliflo vs-svrs. But I've read that this pump works best with 2" piping and I have 1.5". I'd like to do as much as I can myself and I was wondering if it's worth it to change the pipes to 2". The pool has a skimmer and a main drain which seems to not work (the main drain) for some reason (I tried to unclogg it with water pressure but no success; I've heard that it's possible to have been blocked intentionally). If I want to change the pipes, do I have to change the skimmer too? And also, do I have to dig all the way under the pool, to get to the main drain? I'm thinking also to change it to salt water, but I'll leave this for another topic. Any comments and suggestions are appreciated. Thanks. alpop