Wow.... Bleach consumption cut in half with a solar cover

[chem geek]

The ideal cover would totally block UV light so that chlorine won't breakdown from sunlight's UV rays. It would completely pass through visible light and most infrared. It would completely block heat from convection and diffusion (very little gets radiated back out from the pool as infrared -- it's not THAT hot) so would be a good insulator for heat.

I don't think such a cover exists. Most that pass through sunlight seem to pass through a lot of UV. So the clear bubble pack variety are probably best if you want heating since they pass through most of the light while still being good insulators. If you want to minimize chlorine loss, then an opaque cover is best though a blue cover MIGHT block UV (since it reflects blue) while letting other visible light through (or it might let blue light through -- ideally it would be like blue-blocker sunglasses that look orange when looking through them).

My own pool cover is an opaque safety cover and changes the heat loss at night from around 6F without the cover to 3F with the cover. If I had a true solar cover (bubble pack) the pool would probably lose half what it currently does -- probably around 1.5F. But at least I can roll mine with an electric motor so the convenience outweighed the lower insulating efficiency.

Richard