I'm hesitant to use chemicals and antibiotics. Most of the beekeepers at the local club think that is naive. I have seen colloidal silver clear up bacterial and fungal infections in people and animals. I think its safe, so I've been adding it to the syrup on my new colony for the past week. I'm not sure how much to give them. I also am considering spraying them with colloidal silver when I open the hive again in a few weeks. Has anyone used colloidal silver?