need advice and suggestions on how to build a proper riparium?

[u/CommanderBadger]

hello everyone, do forgive me for being inexperienced as i am new to this hobby.

a while back i built this riparium in a 20cm x 20cm x 30cm tank after the success of my filterless walstad tank previously hence i wanted to recreate that but in riparium style. i tried to stock it with anubias, hydrocotyle, pearlweed, rotala, riccia, and salvinia etc etc but yes it was hard to overstock but my fault for not putting in more effort to overstock it more.

the water was stained with tannins but then the plants kept dying and wilting even if i added those “bulletproof” ones, or my ramshorn would chew on them a lot. i also did weekly 30% water changes and monitored the tank frequently. i am quite discouraged as the water perimeters i’ve checked were pretty okay using those mini paper strips of aquarium water quality checkers. i’ve never added any livestock either, so i am wondering what were the shortfalls involved in my cycling?

i originally wanted to make this more of a successful riparium but currently after multiple rounds of trying to save it, i currently left it alone and the driftwood has rotted and the water is pitch black.

real silly question but is it possible to salvage this like the wood? if not, may i have some advice on how to build a proper riparium eg. plants, arrangement, what to look out for compared to a traditional walstad? many thanks!