I took the cover off a week and a half ago and left the pump running all week while I was SLAMming the pool. When I started my water level was a little high but I had to backwash a few times and that brought it down to just right. Come the following Friday (1 week later) I was sucking air through the skimmer. Here in the Cincinnati area it was rainy and mild most of the week so I'm pretty sure I didn't lose it to evaporation. Once I noticed it was losing the water I turned the pump off for a day and the level was unaffected. So I'm thinking I have a plumbing leak. This is the first time I have opened a pool and now I'm worried that I'm looking at thousands to get the plumbing fixed. I have been reading this forum since we decided to buy the house last spring to learn what I can. In my reading the last couple days, it seems like this would be a pressure side leak since I'm losing water and not getting air in the pump basket. If the lines have to be replaced, how do they do it? Do they have to dig them out (in-ground pool)? If so, this is going to be a painful fix as my back yard is a hill and the pressure lines are on the uphill side with a retaining wall just past the concrete pad. Can someone give me a little direction here please?