I used to have a 60 gallon tank 19 years ago, before immigrating to the US. I don't know if you consider fish from the Amazon to be fresh water or not. However, I would love to have a tank like it again. I remember sitting in front of the tank for hours, rather than watching TV. I had real plants in the tank, 12 Neon (the real ones), 4 Scalar (I think you call them Angel fish), and many other colorful varieties.
Yes, amazonian river type aquariums are freshwater. It is very soft and acidic and full of rich tannins. It can almost have a reddish tint from all the rich natural nutrients found in the amazonian rivers.
Aquariums do have a very relaxing effect on people. I too used to love being able to sit in front of mine. Watching the fish swimming so beautifully around. Knowing the science behind the beauty. The whole ecosystem working so perfectly. Knowing that if I needed to, the water was so pure, you could drink it. It was a feeling of accomplishment.
Seeing the little babies darting in and out of the rocks to grab some of the food not gulped up by the adult fish. To see the fish grazing on the good green algae and small snails too. The snails were wonderful too, doing their part in the balance of things, burrowing thru the gravel , eating the excess debris and food, keeping the gravel aerated.
WHen you finally have it balanced an aquarium hardly needs maintenance, just an occasional inspection of the bio material in the filters to make sure there is no clogging etc. Its a plus to find snails living inside, it means things are balanced. I never minded algae, good green algae. It simply meant things were healthy. Most people dont understand that you dont want to over clean aquariums. Many people kill their fish with over cleaning. An aquarium works by having the balance of beneficial bacteria that covers every surface , every rock, and most important the gravel. If you vacum the gravel you end up destroying the flora of bacterial filtration.
I could go on, but I wont. I love it.
amazonian biotope tanks