We are installing a new "uni-bead" liner in our 12x20 oval pool. We have a water truck scheduled for 10 am tomorrow morning. My question is, can we go ahead an put the liner in today and fill it with a little water? We just want to get started, but we don't want the sun to shrink the liner. It's supposed to get to 90 degrees here today in Pennsylvania. Any suggestions on the timing of everything?