Try play sand from Walmart. It's inexpensive and actually looks quite good. If you don't mind a color like blue or green or pink as your sand color. I have blue in my growout tank and it's great.
Yeah it's awesome! I had gravel for years but the black sand is awesome. I am going to get another 50 lbs to add to my tank just for that extra layer. Glad it worked out for your tank. Post pics when it settles.