Changing sand is an absolute *&$#%.

I have a DE filter now, but vividly remember the sand filter days.

Our sand filter took 150# of sand. Due to pool store ineptness, I was convinced I had bad sand two years in a row, necessitating a breakdown and replacement mid season.

Only way to get to the sand was to screw the head off the filter, use a ladel or something similar to dig the sand out. I'd reach a point where I'd get frustrated and just pick the thing up and dump it into a wheelbarrow, but my back paid for it for awhile after...

Knowing what I know now about pool operation from info learned here, I look back on my past years of pool store supported pool ownership and want to cry at the labor and money wasted.

Have you cleaned your pump basket out? If you haven't cleaned it out since opening your pool, chances are good there's a lot of gunk in there that is blocking good water flow.

I'd check every possible source before I'd consider changing sand.