I'm trying to get a fair approximation of a gritty mix made up but have come to the granite grit and want advice on it. I don't have a tractor store or a feed store nearby so I'm wondering if this mail order supply place for orchids has the granite chips you all are talking about. What size would I need? How about Aquarium gravel? I use the colored kind already in my daylily mix, would that be appropriate or would a fish supply store carry granite chips perhaps?......Here's a link to the on line granite chip place: Orchid potting media .......Maryl