Brennan's Better Ballast is made from real crushed granite. It has a prototypical gray color blend and is accurately sized for 1/48 scale. It's the most realistic looking O Gauge ballast I have ever seen. It comes with complete and easy instructions for ballasting and weathering to create a naturalistic look. There is nothing else like it on the market. See for yourself why it's better!!
What kind of track are you using? A 5 pound bag of my ballast will cover 22 feet of Atlas O or GarGraves track ballasted even with the tie tops and with a gentle slope along each side.