my buddy is using it in their planted tank and it is working really well, but you can get it from lowes or home improvement stores in pool season or from pool/spa maintenance stores
The sand is fine, I would just put a layer of organic potting soil first, then use the sand over it to Trap it to keep the water clear. Then your plants will grow great from the nutrients in the potting soil, and the sand will keep the soil out of your water. be sure to fill the aquarium very, very, very slowly to keep the sand from being swished around and letting the potting soil out.
I actually got my sand from the bottom of a dry river in the winter months when the river was low. there are certain places where sand collects (sandbar) from the swirling current of the river. I would just thoroughly wash the sand
I got some from Lowe's the other day. It was larger gravel size then "sand" which is not good for aquariums and clouded my water. Even when I rinsed the gravel.
I went to a actually pool supply store bought some 50lb bags for 7.50, and that's the good stuff. So i would stay away from Lowes/Home Depot for sand.