I think it depends on what you are using the sand for... plants, saltwater tank, just a decor.
For plants, you can go with a simple play sand that is safe for aquariums.
Saltwater, i believe that you would be safer getting a sand that is meant for saltwater tanks. Better safe than sorry.
And if its just as a decor.. well, i would think that you could get just about anything as long as its safe in the aquarium.
As with any new tank addition, you will want to make sure to clean and dissenfect it.
Another thing... if this is a currently running tank, this might change the cycle if you arent adding any plants. If its a new tank, then be careful about adding anything new. expecially fish.
I dont know a lot about the sand yet, but i will be starting my first planted tank here soon.
I hope that someone else that is more knowledgeable will come a long with some better advice. But, to be safe... i would wait for another responce or two before jumping the gun on a purchace.
Only because i dont think i have helped much..
Good luck.
Janell