Another sunset in paradise

Revised. So how does one get rid of grainy sky?

Great nature colors David, Nice shot

Try selecting the sky and filter/noise & dust radius 2, threshould 1. Try a few different attempts with different numbers 1,1 2,2 etc. It will blur the clouds a little but since there isn't any sharp edges it's not to bad. You can always go back and run an USM against it.