u/AdSecure6406

I have a 4 year old 24 foot round above ground. The issue is keep having is frequently needing to backlwash because the pressure of the water on the flow return is low. I can backwash in the morning and have great pressure but by the afternoon it is slow again. We just did a sand change a few weeks ago and the pressure was great for about a week but has returned to needing a backwash everyday or low return flown

I know i should not need to backlash everyday. The water is perfectly clear. Any ideas of what it might be?