Nealf, you make good points on high tech aquariums as far as energy use and water waste. Personally, I'm planning on a big low tech tank as soon as I can save up the money and work out the many details, because it is appealing to me also -- mostly because I'm lazy, I suppose. Low maintenance is good for me timewise, and there are the added benefits of less waste.

However, the high tech tank environment is natural in some areas of the world, and we are just duplicating those environments. There are high light areas with CO2 springs and plenty of nutrients. If those areas did not exist, the plants we use in a high tech tank would not exist in their current form. So, I still see high tech tanks as natural. Some of the high tech plants are beautiful, and we will not be able to duplicate their look in our low tech tanks.