There's a few different choices.
PFS ... cheap and abundant at Pool supply stores. Gravel vacs are the best way, PFS is coarse enough to not get completely get sucked up a gravel vac. I stick the vac into the sand to stir it up then let it fall back down. Personally I'd say avoid playsand as tends to be finer and suspends easier than PFS.
Sand needs a thorough cleaning which means a lot of rinsing. I boil mine which I find releases more of the dust that just clings onto the sand particles.