Also, you should never have to replace the sand in a sand filter unless some additive has gummed it up. We moderators all use sand filters and none of us changes our sand. Mine is the "youngest", in its 9th season with no problems.
That doesn't mean we endorse sand filters over cartridge or DE filters.

All three can do a marvelously fine job if sized and set up correctly, and then maintained correctly. If you are having a problem with your filter, and your filter is undamaged, it's either due to another part of the system having a problem or the filter's too small for the pump, the pool, or both.

Carl