I'm new here and have been reading a lot about different methods of keeping your run mud free (I live in rainy Seattle). I keep coming across sand. However, It seems that most sand has silica in it. Personally, I don't use commercial cat litter since it contains silica and can harm the cats lungs when they scratch. I don't see how a chicken would be any different. IS there sand without silica in it or are chickens not affected by it? Same with DE, contains silica and I get if you use human grade its less, but its still there. Am I just too much of a city girl and care about things that I'm sure most others don't?