I have two drums that I picked up today for 20 bucks. Both of them have have not for food or drink stamped on them. That was my first flag. When I asked he guy I got them from were they came from since I specifically asked for food grade barrels. He told me that the barrels came from a company that stores food grade dye in them and that he cleaned them out with a sodium hypoclorate solution. What do you guys think about the safety of using them for filter s for my pond. My thinking is that if it had food grade dye in it then it couldn't really be that bad. The cleaner he used is used in regular soap and from what I can tell is also used in sanitizer for beer and wine making. My plan is to fill them up with water and let them sit for a few days in the sun to get them nice and hot to try and get anything that is left out. It is August and the barrels are black so I figure that they are gonna get pretty hot sitting in the sun all day. What is everyone's thoughts?