your problem is completely different than my concern but i thought this wasn't a bad location to add a question ...

this was our first winter with a similar safety cover. when the cover was removed the water level was "right on" -- almost zero water needed to be added or removed

sounds great but this spooked me ...

what if the water level got to that level during the winter, froze and had cracked my lines? is this a concern that anyone else has with these covers? do you check water levels at regular intervals during the winter?