I've always seen labels read "Plant in fast draining sandy location or container" Is this like play sand? I cant imagine it would be silicon sand? I have clayish soil and was told adding sand would help it out alot, but wasnt really told what kind of sand, or if the same sand can be added when potting citrus or cactus. I've been told mulching with sand keeps bugs down in the Greenhouse, but what type to use? I had no idea there was so much sand to choose from! Is anyone else as lost as I am when it comes to grain?