Thanks to covid-19 trying to find a solar pool cover locally for our 27ft round pool that only gets about 4 hours of sun a day is tough. A friend of our just recently installed his pool and it came with a solar cover however his pool is only 21ft. I seen another post with a similar question but my gap would be 3 ft around exposed to air. Do you guys think it will still work for the most part or is the idea to have entire pool water surface covered? BTW it was selling for 50$ is why i am eager to buy it and its new.