For certain biotopes, you can easily find driftwood from the appropriate area, and even add leaf litter from trees appropriate to the biotope that area you are trying to recreate. However, for Amazon biotopes, finding region-specific driftwood, rocks, leaves, and the like is difficult, if not basically impossible. So, I avoid the description "biotope" when talking about my tank, which features apistograma, tetra, and some South American plants. I avoid that description because my driftwood isn't Amazonian, not all of my plants are South American, and I don't think adding Indian leaf litter would help it's case. But, there aren't any official guidelines, and no apparent consensus on the issue. My standards might even be too high. So, what, in your mind, are the minimum requirements for calling your tank an Amazon biotope? How strict are you?