I am hoping someone can help me!! I recently bought a house with a built in gunite pool. The pool was installed in 1968/1969 by Wagner Pools of CT. I opened the pool and figured out a lot of the workings, however I'm still at a loss on a couple of fronts. First my skimmer has two drain hole in the bottom - the first is for the filter pump - I'm at a loss for the second hole? I do have several drain pipes the drain behind the pool house- I did put drain plugs in the well, but I want to know - should the winter plug be left in this drian hole while running the pump? Secondly, I have a bottom drain and do not know how to access it or do not know if it works as part of the filter system? Can anyone help?? Also the tiles at the top of the pool need replacing - is this something I can do myself?? If so how?