A 10g is rather small for three of these toads. I would suggest a 20g long (I used the regular 20g high) would be the minimum size for three toads. These amphibians (Bombina orientalis) spend a lot of their time in the water, unlike the more usual terrestrial toads and they will appreciate room for swimming. They are more frog-like than toad-like, though they are true toads.
I had a Red Belly Toad for 20 years. I took a 20g aquarium and siliconed two pieces of 6-inch wide glass across it an angles to divide the "floor" space so I could have water on the front side and gravel on the back. I placed a couple chunks of wood and some small river rock on the gravel part. Java Fern was attached to a small bit of wood in the water part, and regular ferns grew with their roots in the gravel.
The Bombinatoridae family, one of several in the order Anura [Frogs and Toads], holds two genera of warty, aquatic toads, Bombina and Barbourula. The genus Bombina, erected in 1816 by the German naturalist Lorenz Oden (1779-1851), holds eight species. Four of these, Bombina bombina, B. variegata, B. maxima and B. orientalis may be seen in the hobby, but by far the most common is the latter. Fossil Bombina are known from the Pliocene epoch (2.5 to 5.3 million years ago) through the Pleistocene (11,700 to 2.5 million years ago).
Byron.