My three dear hens are very sick with a respiratory disease and antibiotics in their water didn't work. I have been advised to cull them all, spray everything down with bleach water, and then wait a month before getting any more hens. I never want to have to go through this again, so I really want to make sure any new hens don't catch the same sickness from my environment. I can't bleach my grass, can I? Someone else advised me to wait 6 months before getting new hens. I don't know what to do, and the whole situation is incredibly sad for me. Any advice would be greatly appreciated.