fatcat07, I have about the same size as you but sloping sides make it 24400 gallon.
as for the so called solar cover. it is only good to keep the heat in.
if you might get a inexpensive temperature gun;
http://www.walmart.com/search/?query=temperature gun
like one of those, got mine on sale at amazone. I use it to see what local temps are.
the concrete around my pool walkway heats to 105 on a day like today.
the water can greatly absorb some of that suns heat if the cover is off.
I took my solar cover as big and bulky as it was, cut it into 4 sections so I can handle it by my self.
when temps are right I roll the covers up and set them aside until the sun is
no longer on the water. then I quickly roll each cover for the night ti help keep the heat in.
you also have to realize, when you are warming up the water it is not just the water that
needs heating. the mass around the pool like the gunite or concrete surrounding the pool
needs to be heater too. that is the why it takes so long.
I am fortunate to have my pool filter assembly sit in the winter/spring sun early in the day
till about 2PM. I used the bought temp gun and walked through a mall parking lot. I was looking
for the car with the hottest paint color. I painted my filter and plumbing with that color auto
paint. today I can say it almost gains me 3 degrees heat. I also lay my pool vacuum line on
the hot pavement (105degrees) and gain a bit there too sitting in the sun too. with out a heater my pool today
is up to almost 76 degrees. it is work but I am retired and have the time to work it.
the solar cover to me only helps maintain the temp over night......a cold one I loose a few.
one more thing, if you have jets, be sure to have the deep end one pointed to the bottom to
bring up the cold from there..