Except for wiping off the glass, trimming plants, a bit of top dressing on the substrate occasionally, and doing occasional water changes or partial changes in the aquarium or water sections, a planted vivarium with dart frogs will last 5 or more years without a major overhaul. Algae, slime molds, some moss will grow on water falls and logs, but this is only a part of the biological system. Whatever you use for material for the falls will become colonized with various organisms, including nitrifying bacteria, which are not unsightly and actually help "filter" the water.
It seems ironic, but the most successful fresh water tropical fish tank I've ever had is part of a 135 gallon palludarium that contains various kinds of small tetras and algae-eaters. After 7 years, I still have many of the original fish, and have never done a complete cleaning, only rare partial water changes and adding water as needed. The only filters are two water falls and a "river run" of small falls covered with mosses, and lots of aquatic plants. After the first year, there never seemed to be a significant amount of algae on the inside of the aquarium glass, even though the entire tank is well lighted with two double tube 40W fluorescent hoods of different spectrums. It also gets some slanted late evening sunlight during the winter season.
I'll be uploading some photos of the D. galactonotus that are in there, taken for another purpose, but this does show some views of the various plants and algaes that make up the system and contribute to its over-all health. You can't really expect your system to look as pristine as one needs to keep a salt water aquarium, because the success of a planted dart frog vivarium depends a lot on natural recycling of the frog feces, which sometimes involves algaes, molds, tiny soil critters of various sorts, sometimes including little millipedes, that are otherwise harmless, but scare some people. Even though newly set-up vivariums may look pristine and ideal, they never stay that way over time, but actually become more "healthy" as "stuff happens."
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Patty
Pahsimeroi, Idaho
4 D. auratus blue
6 D. galactonotus pumpkin orange splash back
7 D. imitator
6 D. leucomelas
6 D. pumilio Bastimentos
4 D. fantasticus
6 P. terribilis mint and organe
4 D. reticulatus
4 D. castaneoticus
2 D. azureus
4 P vittatus
2 P. lugubris