OK, so I need to purchase a winter cover for my 24' radiant pool. As you can see in the photo I recently had a block wall installed around the pool with stone coping. The measurement from the outter edge of the coping to the other edge measures 26'. I typically lower the water level in my pool below the return so thats about 17" below the top edge of my coping. Any suggestions on what size cover and best way to secure it.