Many of the big box stores sell only play sands, which are inexpensive, but very dusty, gritty, and insufficiently dense, so that the grains may free-float when disturbed, get easily siphoned up, and may tend to clog up filter impeller assemblies.
Get true # 20 grade quartz-based, inert silica pool filter sand at a swimming pool supply store for around $10. for a 50 lb. bag. It's safe for aquariums, looks good, needs little or no rinsing, and won't display the negative features mentioned above about play sands.