I can't find a proper succulent mix in the stores in my area. Online items too have bad reviews. I still managed to find a product that seems okay. It is silica sand. The product looks like coarse grains almost like rocks. I thought it might be good as it would not retain water. I'm thinking of adding a little bit of dried cow dung into it as a component for nutrition. Is it okay to purchase it or is silica sand bad for succulents? Here is a picture of the product.