Acceptable water loss ??

I'm in the 1st week of my new 1200ish gl pond and after the 1st day I lost a 1" of water.I thought I had a problem but now on day 5 I haven't even lost another 1". So total water loss over 5 days is under 2".I wanted to put fish in it this weekend but I figure now is the time to drain the water and check the liner for holes.
I was wondering what the community here thought? Is there an acceptable level of water loss, the 1st night could have been caused by alot of things : Deer. Birds ect.. I have checked the liner @ the top ring and no problems?
Also If I do drain & check, any tips of refilling it and keeping the liner from having verrtical folds while filling?