"Bigar Waterfall" type paludarium idea

I saw this stunning waterfall from romania called the Bigar waterfall and it inspired me to start planinng a paludarium based on it. This idea is only in its hypothetical stage right now because I don't have space or the resources for the project yet. I just wanted to run it by the experts of this forum to see if its even a viable idea. The setup will only have Romanian animals and temperate flora that is in the location or would be suited to the environment.

Panoramio - Photo of Bigar waterfall -Romania

Animals:
either fire-belly toads (Bombina bombina) or Fire salamander (Salamandra salamandra)
weather loaches (Misgurnus anguillicaudatus)
gudgeon or white cloud minnows
Flora:
Maidenhair spleenwort
Trailing maidenhair
Jori Spikemoss
Ficus pumila
Salvinia natans
Hornwort
Vallisneria spiralis

Setup: 50 gallon tank with about 15-20 gallons of water. The area under the waterfall and half of the tank will be land. There will be two sections of water one fish-less pool capable of breeding that will have a mesh gate so that the pool recieves some filtration and the largest water section being dedicated to fish. The water will be filtered by a DIY canister filter thats capable of large water exchanges which will have the outflow at the top of the waterfall.

I am leaning towards Fire Salamander because they do not enter the water unless they are breeding, so the setup would be split into two distinct parts and I won't have to worry about ammonia poisoning the amphibians. I know quite a bit of the members are against species mixing but I would like to keep this to a factual exchange.

I liked the idea of using Hyla arborea since they would be able to use the most space but alas they are banned in Washington.

I would discard S.salamandra. Yes, they won´t use the water but they can nevertheless drown in it. An animal could fall into it, or take a little dip while exploring or getting out of the way of a more dominant animal, and while the probabilities will depend on the configuration of the tank, there is a risk of drowning.
Also, they like to burrow, which in a complex, divided paludarium may be a problem.
I don´t think this would be particularly suitable for H.arborea either. This species preferentially inhabits reeds and other vegetation around pools of stagnant water. The pressence of fish and a current could be a problem even out of breeding season as these frogs tend to use the water to hide.

It sounds interesting. If the waterfall flows over the moss covered rock instead of splashing it will be less of a mess. I'd put pea gravel, leica, or something similar as a base substrate. The medium for the plants could be separated from the bottom layer with a screen like a synthetic window screen. If to much organic material is in constant contact with the water it will be a cesspool. Another approach would be hydroponic with no organic substrate.

My P. terribilis tank has a water trickle area over an artificial tree root. I have no filter other than the gravel. The pea gravel acts as a huge undergravel filter. This is an old picture of the tank which gives you an idea of the substrate and lay out. The tank is now filled in. It is my favorite tank and has been running for years.

I know it isn't exactly what what you are thinking of but a similar idea. I think you will have more success with a small pump and a big trickle feature than with a huge filter and a big water fall.

I am also not keen on mixed species.

Yes, although I dont mind mixed species enclosures fish and amphibians dont mix naturally, and it would be especially difficult with a small enclosure. I was just thinking out loud with it. Although I wont scrap the tank altogether I will scrap the idea of fish and just have a large healthy group of fire-belly toads in there using a small trickle filter over the top. Thanks for the advice on soil, I have had serious problems with that before. I will most likely start the construction of this tank next year and post it back on this thread. Or I may end up making the tank a non-romanian specific tank and find some beautiful newts that by-pass the strict washington laws.

Thanks for the advice!

You can make very pretty and very functional tanks with the leica stuff and the right plants. I had one for some juvenile B.orientalis i had for a while that worked great and was ridiculously easy to clean and maintain (except for the rampantly growing plants).

Nice waterfall. Check out the one in Baltimore: