I have found all the food supplies needed for my chickens, except for 'grit'. The local feed store told me that "oyster shell' IS grit. Well, I do offer them "oyster shell" free-choice for their egg production, but I've since read that oyster shell dissolves and isn't "true grit" so to speak. Is the black 'granite grit' I saw on this website the type /color grit you have locally? http://www.alibaba.com/catalog/11081194/Chicken_Grit_Granite_Grit_Or_Chips_Regular_Bulk_Supply.html I also looked at tractorsupply website for chicken grit... there was a 5 lb bag for about $6 by Nutrasource described as 'crushed granite". http://www.tractorsupply.com/webapp/wcs/stores/servlet/ProductDisplay_10551_10001_48676_-1______?rFlag=true&cFlag=1 Maybe I asked the wrong person at my feed store, because I can't imagine they don't sell this type product. I'll have to ask again. But I've been in the warehouse and have never seen any in the feed area. I do feed my chickens treats, besides the laying pellets so I want to make sure they get what they need to stay healthy. They are laying now.. yippeee!!! !!!! and I've not seen any sickness in the 5 months, so they must be getting what they need from the small pebbles in the builders grade sand I used in the base of their run... but I worry that that will run out of the right size tiny pebbles in the sand. Is the builders sand pebbles adiquate? (I have seen them pick out the tiny pebbles the size of "rock candy" we used to eat as kids, btw) so I know they DO eat from the sand. One good thing that happened recently is that since I can't free-range because of predators, I now have a moveable run in my backyard for them to forage for greens and grubs, etc... but I still want to know what there is to know about grit for chickens particularly. I'd noticed 'grit' for parakeets in Wal-mart and there was some spillage coming from the small box and it looked JUST like sand, but figured it was Not the right size for chickens. Maybe it's a silly question, but if you have a run in the same place, over time won't the natural 'grit' in the soil be depleted? Ok.. that's about all the questions I have about 'grit' for chickens... Thanks in advance for any light shed on this subject.