Paludarium Guide: How to Build a Half-Water, Half-Land Ecosystem

A paludarium combines an aquarium and a terrarium in one enclosure. Half water, half land, it creates a unique ecosystem where aquatic and terrestrial plants and animals coexist. Think of it as a miniature rainforest with a stream, waterfall, or pond. If you’ve ever wanted to recreate a riverside habitat in your home, a paludarium is the answer.

Paludariums are more complex than standard terrariums, but they’re also more rewarding. You can keep fish, frogs, shrimp, and plants that thrive in both wet and dry conditions. This guide walks you through the planning, building, and maintenance of a paludarium from start to finish.

What Is a Paludarium and How Does It Differ from a Terrarium?

A terrarium is a sealed or open container with plants and soil. A paludarium takes this concept further by adding a water feature. The name comes from the Latin word “palus,” meaning swamp or marsh.

While a regular terrarium is purely terrestrial (all land), a paludarium has both aquatic and terrestrial zones. This allows you to create more complex ecosystems that mimic natural habitats like riverbanks, waterfalls, swamps, and rainforests.

Paludariums can also house animals. Many keepers add fish, frogs, shrimp, or turtles to create a true vivarium (an enclosure with both plants and animals). The water zone provides habitat for aquatic species, while the land zone supports terrestrial plants and animals.

Types of Paludariums

Paludariums come in several styles, each mimicking a different natural habitat:

Rainforest Paludarium

Mimics a tropical rainforest with high humidity, dense vegetation, and a waterfall or stream. Ideal plants include ferns, mosses, orchids, and bromeliads. You can keep dart frogs, tree frogs, or tropical fish.

Riverbank Paludarium

Recreates a riverside habitat with flowing water, rocks, and riparian plants. Good choices include java fern, anubias, and carnivorous plants. Suitable for fish, shrimp, or small turtles.

Swamp Paludarium

Simulates a marshy environment with shallow water and emergent plants. Pitcher plants, sundews, and mosses thrive here. Frog species that prefer humid conditions do well in this setup.

Waterfall Paludarium

Features a vertical waterfall element that cascades into a pool below. This creates movement, sound, and increased humidity. Ideal for mosses, ferns, and epiphytic plants that grow on rocks.

Planning Your Paludarium

Choose the Right Enclosure

Paludariums need a specialized enclosure that can hold both water and land. Options include:

Exo Terra terrariums: Glass enclosures designed for reptiles, with waterproof bottoms and front-opening doors
Custom-built enclosures: Glass or acrylic boxes with a sealed water section
Repurposed aquariums: Glass aquariums with a land section built using foam, rocks, or false bottoms

The enclosure should be at least 18x18x24 inches (45x45x60 cm) to provide enough space for both zones. Larger is better, as it gives you more room to create a natural-looking transition between land and water.

Decide on the Water-to-Land Ratio

Most paludariums are 50/50 or 60/40 water-to-land. The ratio depends on what plants and animals you want to keep. More water gives you room for fish and aquatic plants. More land provides space for terrestrial plants and animals.

Plan the Water Feature

Decide whether you want a waterfall, stream, or still pond. Waterfalls create movement and sound but require a pump and more maintenance. Still ponds are simpler but less dynamic.

Materials You Need

For the Water Zone

Substrate: Aquatic soil, sand, or bare bottom for easy cleaning
Filtration: Small aquarium filter or sponge filter to keep water clean
Pump: Submersible water pump for waterfall or stream (if desired)
Lighting: Full-spectrum LED light for aquatic plants
Water conditioner: To remove chlorine and chloramines from tap water

For the Land Zone

False bottom: LECA pebbles or foam to create elevation above the water line
Barrier: Egg crate, mesh, or fiberglass screen to separate false bottom from substrate
Substrate: Tropical potting mix, coco coir, or ABG mix (Atlanta Botanical Garden mix) for moisture retention
Hardscape: Rocks, driftwood, cork bark for structure and planting surfaces
Plants: Tropical plants that tolerate high humidity (see plant list below)

Best Plants for Paludariums

Paludarium plants must tolerate high humidity and occasional submersion. Good choices include:

Aquatic Plants (Water Zone)

Java Fern (Microsorum pteropus): Hardy, low-light aquatic fern that attaches to rocks and wood
Anubias: Slow-growing plant with broad leaves, attaches to hardscape
Java Moss (Taxiphyllum barbieri): Easy-to-grow moss that covers surfaces
Amazon Sword (Echinodorus amazonicus): Large, dramatic aquatic plant
Water Wisteria (Hygrophila difformis): Fast-growing stem plant

Terrestrial Plants (Land Zone)

Ferns: Maidenhair, button fern, bird’s nest fern love high humidity
Mosses: Sheet moss, cushion moss, fern moss thrive in wet conditions
Bromeliads: Epiphytic plants that mount on driftwood or cork bark
Orchids: Miniature orchids that grow on rocks and wood
Fittonia: Colorful nerve plant that spreads as ground cover
Pilea: Easy-to-grow tropical plant with interesting leaf shapes
Carnivorous plants: Pitcher plants, sundews, and Venus flytraps (for bog-style paludariums)

Emergent Plants (Land-Water Boundary)

Peace Lily (Spathiphyllum): Can grow with roots in water and leaves above
Pothos (Epipremnum aureum): Vining plant that tolerates wet conditions
Creeping Fig (Ficus pumila): Climbing plant that covers surfaces

For more plant ideas, see our complete guide to terrarium plants.

Step-by-Step: Build Your Paludarium

Step 1: Set Up the Water Zone

Start with the aquatic section. Add substrate (aquatic soil or sand) to the bottom of the water area. Install the filter and pump if you’re using a waterfall or stream. Add hardscape elements like rocks and driftwood that will extend from water to land.

Fill the water zone with dechlorinated water. Let the filter run for 24-48 hours to cycle the water before adding plants or animals.

Step 2: Build the Land Zone

Create a false bottom using LECA pebbles or rigid foam to elevate the land area above the water line. The false bottom should be 2-4 inches (5-10 cm) thick. Cover the false bottom with a barrier (egg crate or mesh) to keep the substrate from falling through.

Add 2-4 inches (5-10 cm) of tropical substrate on top of the barrier. Slope the substrate to create a natural transition from land to water. Compact the soil gently as you build the slope.

Step 3: Add Hardscape

Place rocks, driftwood, and cork bark to create structure and visual interest. Position larger pieces first, then fill in with smaller elements. Make sure hardscape extends from water to land to create a seamless transition.

If you’re building a waterfall, position the pump at the top and route tubing down behind the hardscape. Cover the tubing with rocks or moss.

Step 4: Plant the Aquatic Zone

Plant aquatic plants in the water zone. Java fern and anubias attach to rocks and driftwood with fishing line or super glue gel. Java moss can be tied to surfaces or allowed to float. Stem plants like water wisteria are planted in the substrate.

Step 5: Plant the Terrestrial Zone

Plant terrestrial plants in the land zone. Start with the largest plants, then fill in with smaller ones. Cover any exposed soil with moss to prevent erosion and create a finished look.

Mount epiphytic plants like orchids and bromeliads on driftwood or cork bark using fishing line or hot glue.

Step 6: Add the Water Feature (If Using)

If you’re building a waterfall or stream, turn on the pump and adjust the flow. Make sure water cascades smoothly and doesn’t splash excessively. Route the return flow back into the water zone.

Step 7: Cycle and Stabilize

Let the paludarium run for 2-4 weeks before adding animals. This allows the water to cycle, plants to establish, and the ecosystem to stabilize. Monitor water parameters (ammonia, nitrite, nitrate) during this period.

Caring for Your Paludarium

Water Maintenance

Perform partial water changes (20-30%) every 2-4 weeks to keep water parameters stable. Use a gravel vacuum to remove debris from the substrate. Top off evaporated water with dechlorinated water as needed.

Test water parameters regularly. Ammonia and nitrite should be zero. Nitrate should be below 40 ppm for fish, below 20 ppm for shrimp.

Lighting

Provide 8-12 hours of light per day using a full-spectrum LED. Adjust the photoperiod if you notice excessive algae growth. Aquatic plants need adequate light for photosynthesis, but too much light encourages algae.

Pruning and Maintenance

Trim terrestrial plants regularly to prevent overcrowding. Remove dead leaves and algae promptly. Aquatic plants may need trimming if they grow too large or block light.

Clean the glass as needed to maintain visibility. A magnetic algae cleaner works well for accessible areas. For tight spaces, use a razor blade or algae scraper.

Feeding Animals

If you keep fish, frogs, or shrimp, feed them appropriately. Fish need species-specific pellets or flakes 1-2 times per day. Frogs eat insects like crickets, fruit flies, or waxworms. Shrimp graze on algae and biofilm but benefit from supplemental shrimp pellets.

Avoid overfeeding. Excess food pollutes the water and causes ammonia spikes. Feed only what animals can consume in 2-3 minutes.

Common Paludarium Mistakes

Mistake 1: Inadequate Filtration

A paludarium with animals needs proper filtration to keep water clean and safe. An undersized filter leads to ammonia spikes, cloudy water, and sick animals. Choose a filter rated for your water volume and clean it regularly.

Mistake 2: Overcrowding Plants or Animals

It’s tempting to pack a paludarium full of plants and animals, but overcrowding leads to stress, competition, and poor health. Give plants room to grow and animals space to move. Research the adult size of all species before adding them.

Mistake 3: Skipping the Cycling Period

Adding animals before the paludarium is cycled is dangerous. Beneficial bacteria need time to establish in the filter and substrate. Without them, ammonia from animal waste builds up and kills fish or frogs. Always cycle for 2-4 weeks before adding animals.

Mistake 4: Choosing Incompatible Species

Not all animals can coexist. Fish may eat shrimp. Frogs may eat fish. Research compatibility before combining species. When in doubt, keep species separately.

Mistake 5: Ignoring Water Parameters

Water quality is critical in a paludarium. Test ammonia, nitrite, nitrate, pH, and temperature regularly. Stable parameters are more important than perfect parameters. Sudden changes stress animals and lead to disease.

Animal Options for Paludariums

Fish

Betta fish: Colorful, hardy, but need warm water (78-80°F / 25-27°C)
Guppies: Small, colorful, peaceful community fish
Tetras: Schooling fish that add movement and color
Corydoras catfish: Bottom-dwelling scavengers that clean up leftover food

Amphibians

Dart frogs: Colorful, diurnal frogs that thrive in high humidity
White’s tree frog: Hardy, docile frog that tolerates handling
Pacman frog: Sedentary frog with a big appetite

Invertebrates

Neocaridina shrimp: Colorful shrimp that eat algae and detritus
Amano shrimp: Larger shrimp that are excellent algae eaters
Isopods: Clean-up crew that breaks down organic matter

Your Paludarium Journey Starts Here

A paludarium combines the beauty of an aquarium with the lushness of a terrarium. With proper planning, the right materials, and patience during the cycling period, you can create a stunning miniature ecosystem that thrives for years.

The key is understanding that paludariums are more complex than regular terrariums. They require water maintenance, filtration, and careful species selection. But the reward is a dynamic, living habitat that brings the beauty of nature into your home.

Ready to explore more? Check out our complete terrarium guide for everything you need to know about building and maintaining all types of terrariums.