My 30 gallon paludarium tank was actually an unheated tank that I originally designed for fire-bellied newts. A paludarium is just a fancy way of saying a tank with water and land. When the newts decided they would rather stay terrestrial, I decided to add fish. This was an unheated, colder water tank (between 55-65°F). Despite being a cold water tank, there were still some fish that could live in that temperature range. It was home to 6 Peppered Cory Cats, 5 Zebra Danios, 2 Giant Danios, and a few snails. It also had some cold water plants living in it as well, mainly moss, anacharis, java fern, and ludwigia. For lighting I used the Current Satellite from my old 30 gallon reef tank.
Despite being that cold, the cory cats regularly spawned, leaving their eggs stuck to the glass. All the other fish appear very active and healthy. I eventually was able to hatch the eggs and raise the fry. There was at least one female, possibly two in the aquarium, and they feel right at home with the sandy bottom. They usually laid eggs shortly after I fed the tank frozen blood worms.
The background of this tank was actually made from expanding foam covered in coconut bedding. There was a drip system to have water circulating through the whole system and pumped on parts of the background as well as a little stream.
But the fish ended up being the main attraction of the tank, because the “newts” hid all day unless I was feeding them.