I have a 24' round pool and recently purchased a 106k btu Rheem heater. I'm looking for something to try to retain some of the heat overnight. I'm thinking about getting a regular solar blanket cover, but since i have to keep the pvc fencing around the pool, it think it's going to be difficult to put on and remove every day - and I'm wondering if it will get sucked into the filter housing if I run the filter while it is on. Has anyone tried the solar rings and had any success? The heater will take care of heating the pool for the most part, I'm just trying to retain that heat on chilly nights (and being in the Chicagoland area means crazy swings in weather, especially this year!). Any suggestions?