Building a Paludarium: Where Aquascaping Meets Terrariums

A paludarium is what happens when someone looks at an aquascape and thinks, "what if it kept going above the waterline?" Part aquarium, part terrarium, a paludarium replicates the transition zone between water and land, a riverbank, a flooded forest edge, a mossy waterfall cascading into a clear pool. It is the most immersive and naturalistic setup you can build in a glass box, and it combines every skill from both the planted tank and terrarium hobbies.

Types of Paludariums

The Waterfall Paludarium

The most popular style. A waterfall or stream flows from the above-water section down into a pool below. The water area can house fish and aquatic plants while the land section features tropical plants, mosses, and potentially amphibians. Visually dramatic and endlessly customizable.

The Riparium

A simpler version where emergent plants grow from the water surface using floating planters or attached to hardscape that extends above the waterline. Less construction, more plant-focused, and easier to maintain than full paludariums.

The Full Biome

An enclosed paludarium with a sealed or semi-sealed top that maintains its own humidity cycle. These can house dart frogs, tree frogs, newts, and other amphibians alongside fish and invertebrates underwater. The most complex to build and maintain, but also the most rewarding.

Construction Methods

The Great Stuff Method

Expanding foam (Great Stuff Pond and Stone is the aquarium-safe version) is the most popular construction material. You build a foam foundation on the back and sides of the tank, carve it into shape after it cures, and cover it with silicone and coco fiber, tree fern panels, or cork bark. Water channels and planting pockets are carved into the foam.

The Hardscape Stack Method

Stack rocks and driftwood above the waterline, creating natural shelves and pockets for terrestrial plants. Simpler than foam construction but limited in design flexibility. Works well for smaller paludariums where a natural rock face or wood stump is the aesthetic goal.

The Divider Method

Install a physical divider (glass, acrylic, or egg crate covered with mesh) that separates the water section from the land section. Fill the land side with substrate for terrestrial plants. The simplest construction method but creates a visible separation between land and water.

Aquatic Section

The underwater portion follows standard aquascaping principles. Suitable plants include:

• Anubias (attached to wood that extends above waterline, the leaves above water grow differently)
• Bucephalandra on submerged rocks
• Java moss and Christmas moss on submerged hardscape
• Monte Carlo or other carpet plants if lighting reaches the bottom
• Cryptocoryne species for the substrate

Fish suitable for paludariums include small, peaceful species that do not jump: pygmy corydoras, ember tetras, endler guppies, and cherry shrimp.

Above-Water Plants

The Transition Zone (Partially Submerged)

• Spathiphyllum (Peace Lily): Roots can be submerged while leaves grow above. Iconic paludarium plant.
• Pothos: Roots grow into the water and act as a nutrient export system. Nearly indestructible.
• Monstera adansonii: Trailing vines with dramatic fenestrated leaves.
• Ferns (maidenhair, bird's nest): Love the humidity above a water section.

The Land Section

• Tropical mosses: Sheet moss, mood moss, cover the hardscape for a rainforest floor look
• Selaginella: Fern-like spikemoss that thrives in high humidity
• Bromeliads (small species): Stunning in the upper canopy of the build
• Orchids (miniature species): If humidity is maintained above 70 percent
• Fittonia: Colorful nerve plant that loves wet, humid conditions

Water Circulation

A small aquarium pump circulates water from the pool section up through tubing to the top of the land section, where it flows down as a stream or waterfall back into the pool. This creates the water feature visual and keeps the land section's substrate moist. Use a pump rated for the vertical lift height (head height) of your build.

Maintenance

• Water level: Evaporation is significant in open paludariums. Top off with distilled or RO water every 2 to 3 days.
• Pruning: Terrestrial plants grow fast in paludarium conditions. Trim monthly to prevent them from blocking light to the aquatic section.
• Water changes: Standard 15 to 20 percent weekly for the aquatic section. Siphon from the pool area.
• Misting: If the paludarium is open-top, mist the land section daily or use an automatic misting system.

Plan your aquatic section volume with our tank size calculator. If you are including CO2 for the underwater plants, use our CO2 dosing calculator, but remember that gas exchange from the waterfall reduces CO2 efficiency.