I wish I could help out, but I've only used one brand of DE, and that is Red Lake DE , which is food grade. It is a light gray, very very fine. It does its job well when it comes to drying out chicken poo. Costs me 14$ for a 40lb bag. I just ask my local feed mill to order an extra bag with their next usual shipment, since they use it in some of their feed mixes and don't regularly stock it for customers unless asked.