Okay - so I've built my own SOLAR COVER reel and actually have a place on the side of the fence to STORE the rolled up cover but it's just as easy to leave the 'reeled-up' cover on the pool. This means it's exposed in the sun - like when it's ON the pool.
So, I've seen and heard about covers that you put OVER your SOLAR COVERS - what's up with that? Are they absolutely necessary? What's the harm if you don't COVER the COVER?