pool filter sand is a tad bigger than playsand, and settles quite easy. just mix it up really good in a bucket with extra water, then with the tank mostly full scoop up half cups of sand (use a large plastic drinking cup, fill it half way) and slowly submerge and then pour the sand out spreading as you go with the cup barely above the bottom glass.
For cleanings, gently wave your siphon just above the bottm, and then vacuum up whatever floats up in the eddys/current you create. the heavier pool filter sand can even be slightly stirred with a weak simple siphon going and hte sand will just fall out if you lift it a few inches above the bottom.