what type of sand to use?

I bought a 50 lb. bag of playbox sand for a few bucks. Used a frypan on the stove and dried it. (better than sun because the sand gets really dry, drier that humidity of air..) then as it is still warm put it in Ziplock bags. So the sand is very dry and ready for use. I packed three large steel racks with this stuff. i did not need the alien area 51 sand, as i AM a alien. That stuff is sucky... It is from a planet NO ONE would get sand from unless they were YB'Gzains.. and we all know what morons they are. Proof is: why did they crash? huh? tell me... morons...
(At least I just ran out of frit-48 gas... )

Silica sand it what you are looking for.

Should be fairly easy to find, as it's used for sand blasting (bone dry if stored properly and inexpensive).

Wear a breathing mask/cloth when pouring it as the dust is not something you want to inhail.

Perform the task outdoors.

Research silica sand for your application in order to judge the previous sandbox responses to your query.

If someone presents the opinion that there is a sonic difference between silica sand, play sand, cat litter or any other sand when loading audio stands or platforms, then it'll be time for me to leave this insane past time.

That anyone has possibly spent their time making such a comparison is almost beyond comprehension.

Almost.

I used washed sand in my speaker stands.

The best sand in the world resides on the beaches of Port St. Louis in the Maritius Islands... off the SE coast of Africa.

well... there and the Saychelles.

If money is tight though... Palma de Majorca will probably do almost as well... off the S coast of Spain.... and the night life is better.

take along some sealable freezer bags and SPF 40.