this is a great innovative approach. It reminds me biomimicry, because this approach is similar to what happens in rivers. It's amazing that there's no need for electricity, filters, ... but just for Betta fish. FAQs says that
The aquarium should only be used with Betta fish. Most other types of fish require filtration and more space
source
But I hope scientists will be able to create something similar for other types as well. useful hunt. thanks for sharing )