I see this forum doesn't get a lot of traffic but I'm going to give this a shot anyway. I just stumbled upon an old aquarium that I'd like to turn into a begonia house. The problem is that it was covered in layer after layer of hard water deposits that were so thick that I doubt a hammer and chisel would have touched it. I was finally able to get the worst of it off but I had to use every cleaner in the house to get there. Now I'm concerend how to get those chemical residues off the surface so as not to contaminate the plants. Does anybody have any ideas? I'm not really sure how pristine the container has to be to make the environment safe for the plants and I hate to fail before I even start.