I'm new to liner replacement and just had a contractor replace mine which is rectangle shaped. I'm not sure what radius corners he specified to the liner company, but one corner has a good fit, but the other three are taut across the corner with about a 6" x 6" x 12" triangular space from the ground up to about a foot form the top. The pool is filled up and the top of the liner is staying in the coping at the corners. The temperature is in the 40's here in Virginia. The contractor is saying after the temperature warms the liner will relax and seat properly in each corner. Right now, it just looks like the liner doesn't fit correctly. My first thought is, that he could drain the pool down and heat stretch the liner in the corners. Does anyone have experience with this? Does anyone know if liners relax this much over a 30+ degree change in temperature?