Pool Filter Sand

Filter sand is considered inert, it does not change water chemistry.
It is also heavier than lighter sands, such as play sand, it can be vacuumed, and is not quite as easily stirred up as play sand, so should not effect your filter. Although I would not put your filter intake tube too close, just to be safe.
Debris does not sink in, like normal gravel, so you don't need to jam the siphon tube into the substrate as far, to me, it makes vacuuming easier
I get generic filter sand from a supplier of abrasives, that provides sand to water treatment plants for about 50lbs for $5.
The sand in your link looks like good stuff.
I use filter sand in almost all my tanks.

I would also trim it off to about 3" or more above the substrate, but at closer examination of your video.
It actually looks like the intake tube has a built in joint, at the halfway point, where it s made to separate, that would be perfect.