For the past 10 years I have always used a safety cover year round on my 18' X 36' inground pool. My current safety cover is:
Protex - heavy duty cover with 98% shade.
Previously, when I bought the house, the pool had only a bubble solar cover. However after having pocket gophers, muskrats, squirrels, and rabbits falling and subsequently drowning in the pool, I decided to purchase a safety cover and leave it on permanently. Also this offered another level of safety when we became parents to a toddler/child. The only time the cover comes off is when we are using it.
My question is if anyone has data on how much solar heating BTUs I am missing out on. I realize I am not getting the effects of heating during the day on sunny days, but by how much? My current safety cover is dark green, a very tight weave (98% shade), and does not touch the water surface. The air space between the cover and the water surface gets very hot and is humid. So I am assuming the I am minimizing heat loss via evaporation and the hot air space "may" be helping with heating the water.
Any comments on using a safety cover versus a solar blanket regarding heating and heat retention? Would adding a solar blanket under the safety cover help with heat retention?