A terrarium is usually all land. Add a small water feature and you get a paludarium -- half land, half water -- and suddenly you can keep both a fern and a shrimp in one jar. The water half is where the aquarium skill crosses over.
At a glance
| Container | glass jar or exo-terrarium, 20 cm+ tall |
|---|---|
| Water volume | 0.5 to 3 L for a feature |
| Light | medium indirect |
| What lives there | shrimp, snails, Java moss, marginal plants |
Building the water half
Use a small silicone-sealed dish or a capped bottle as the pool. Plant Java moss and a rhizome plant on the edge so their roots dangle into the water. A tiny sponge filter (see the best fish for a 20-gallon tank: 15 species that thrive) keeps it from going stale. The land half stays planted with the terrarium species GreenNest details in a solid GreenNest water-propagation guide.
Why this is the purest crossover
It is one enclosed world where an indoor-plant hobby and a freshwater hobby share a glass wall. The moss is an aquarium plant; the fittonia is a houseplant. Get the water stable and both sides thrive -- the same nitrogen cycle, just smaller.
