I have six 4 day old chicks who are healthy. However, I would like to have the Corid on hand just in case. I went to Tractor Supply yesterday, but the only Corid they carried was in a bag and it was 20%, and since I read on a lot of posts in the BYC forum that you use 9.6%, I didn't get it. So, since they don't carry what I need, where else can I get it?? Thank you!