I know this is not as cool as the drink dispensers but probably more practical with the internal filter providing some flow
The reason I thought of those limitations is because the REEF VASE is not just a small version of a our fully function home aquariums it was made to be something completely different and thought to be impossible the challenge isn't to make a tiny display tank using all the equipment we normal find mandatory to have the challenge is to make a reef in something that seems impossible.Having 3 types of coral is doable, but what if I want to use a coral that doesn't require light as they might do well in an isolated container and not require constant additions of calcium? Or maybe I want to grow sponges. Why not have the light an option as well. Why not make it 3 or more forms of reef life?
Why no mechanical filtration? An under gravel filter setup run by a bubbler seems practical and would be a good place to place a heater out of site. In addition, the bubbler and heater wire could conceivably come out the opening where a spigot would go, keeping wires and tube out of site.