With the bioactive type setup gaining popularity in the world of keeping exotic pets, the paludarium enclosure presents exciting opportunities for a 3-tiered environment that can house multiple species together in a functioning micro-environment that is both beautiful and self-sustaining in the long run. Here’s what you need to know if you want to tackle building your own paludarium.

The paludarium is an exciting innovation in the world of keeping exotic animals. The name comes from the Latin word ‘palus’, which means swamp or marsh. In line with this, paludaria feature deep bottom sections that allow for an aquatic area, which leads up onto a terrestrial area and then room for a canopy environment as well.

This presents the opportunity to provide an enriching habitat for all sorts of species, including more than one in the same space – with thoughtful selection. A thorough and expert understanding of the species involved is required to house more than one species together, but it can and has certainly been done successfully. Aside from that, providing a beautiful natural environment with aquatic elements will be appreciated by species from those kinds of tropical environments – amphibians especially!

In light of these possibilities, making your paludarium bioactive is a natural choice. Making the environment almost entirely self-sustaining will remove the need for regular disturbance or maintenance of the environment. The animals housed inside will therefore be able to live with minimised stress, and there will be less work in the long run on your part, so you can simply enjoy your animals in their set up with minimal effort.

Paludarium environments such as these are a common exhibit type at many zoos, able to house multiple species together.

WHAT’S BIOACTIVE?

For a setup to be considered fully bioactive, some key elements must be in place.

• Nutrient-rich substrate – the substrate needs to be able to support beneficial bacteria, invertebrates, and plants. It should be tailor-made to best suit the type of bioactive you are making, referring to the habitat type you are replicating. The two main categories would be arid or tropical, but there are finer details to consider when it comes to what the specific plants and animals involved need to acquire from the substrate. It may also need different layers, such as for drainage, as would occur in the natural world.
• Plants – plants are needed to cycle nutrients and moisture in the soil, and to provide refugia for microfauna as well as maintaining humidity. These will also need to be specialised to the habitat type you are creating, and non-toxic to any animals that may ingest the plants. Plants will need correct spectrum lighting to grow.
• Microfauna – these are your ‘custodian’ or ‘clean up’ invertebrates. These can range from springtails, beetles or their larvae, worms, and isopods to name a few. These are essential in a bioactive to cycle nutrients in the soil by removing waste products and aerating the substrate. They’ll likely become occasional snacks for any reptiles and amphibians too, adding variety to their diet.

The benefits of this type of setup are numerous. While it can be a bit of a daunting challenge at first, with some research and planning it can come together easier than you may think. Once completed, the animals housed in the environment will benefit from the natural processes going on, giving them a more enriching life.

Larger animals such as this lovely Chinese crocodile lizard (Shinisaurus crocodilurus) aren’t a compulsory part of a bioactive setup, but they certainly benefit from such engaging environments.

PLANNING A PALUDARIUM

Due to the aquatic element, a paludarium is best suited for a humid, tropical type of environment. Species suitable for this environment range from many amphibians to arboreal geckos most commonly, but there are species from every kind of reptile, amphibian, fish, or invertebrate that could inhabit a tropical paludarium. Species cohabiting is possible with a thorough understanding of the species involved; you should have some considerable experience under your belt and the resources to deal with any setbacks – spare enclosures for separation if things don’t go as planned are a good idea. The animals involved should benefit or at the very least be completely neutral to each other. Do not cohabit as a form of ‘space saving’. Ideally, the species would be from the same biotope – or very similar – so they find the environment equally suitable and enriching.

Once you decide on your species, you need to plan the makeup of the paludarium in line with their natural requirements. How much hiding or climbing do they do? What are the humidity requirements? Heating and UVB strength? Water and substrate qualities? All these factors need to be considered in advance before you start putting things together and well before you add the living inhabitants.

Featured above are just a few species that can respectively suit a paludarium environment. From Left to Right: Guppy (Poecilia reticulata),  Brazilian rainbow boa (Epicrates cenchria), Panther chameleon (Furcifer pardalis),  Red-eyed crocodile skink (Tribolonotus gracilis), Blue poison dart frog (Dendrobates azureus), Chinese water dragon (Physignathus cocincinus), Narrow-bridged musk turtle (Claudius angustatus), Tiger salamander (Ambystoma tigrinum), Mossy frog (Theloderma corticale). 

FIRST STEPS 

Hardware is the first logical step. This includes the general layout of the enclosure and any construction you want to do, such as making a background and attaching bulky decorations for the canopy area. Make sure all decorations and background pieces are firmly in place to prevent any accidents down the road. Because paludaria are designed for water containment, you won’t need to seal it first as you would other types of enclosures.

Backgrounds come in the form of ready to buy foam or wood sheets that you can cut to size or DIY backgrounds utilising cork bark, branches, rocks, expanding foam and resin for a personal finish. Factor in the time needed for materials such as the expanding foam and any coatings to completely dry and air out. You can also carve it to your liking. Resin sealant can then be used to coat it, and you can add colours and textures for the final look.

An example of a textured background in a live terrarium – easily applicable also to a paludarium by sticking substrate to a foam/resin base. 

Once everything is dried and stable, it’s a good time to get your aquarium section ready with the necessary filters, heaters, aerators or decorations next. You can add your submerged substrate and partially fill the water section (about a third) with dechlorinated water to allow things to begin to acclimate and monitor that everything works correctly.

Next are the electronics relevant to the terrestrial inhabitants. A suitable UVB tube should be used for amphibians and reptiles, and correct heating/lighting. This is of course tailored to the species you will be keeping, but in most cases an incandescent light works well to provide thoroughly warming near infrared as well as a perception of day/night alongside the UVB.

Live plants in the paludarium will also need specific lighting to provide the right photosynthetic wavelengths that allow them to thrive. The New Dawn Plant LEDs by Reptile Systems are one good example of this lighting, or compact canopy tops that combine UVB and plant growth lighting in one. You can also add misting, fogging, or dripping systems to your paludarium if you want to use one for your inhabitants.

Plant chlorophylls absorb wavelengths in the ‘blue’ and ‘red’ areas of the light spectrum to undergo sufficient photosynthesis.

MAKE YOUR BED

There are many substrates and combinations of substrates suitable for tropical setups such as this, but the most important thing is that it needs to be ‘non-sterile’ and nutrient-rich so as to properly support the plants and microfauna. Bio Life Forest by ProRep is a good example and there are many more options out there that are safe for use with exotic species. You can add other elements such as mosses, sand, leaf litter and coco coir. Some are already pre-made blends. Experiment and research choices made by others successfully maintaining the same kind of enclosure you have set out to find inspiration and advice.

It is important to include a small drainage layer to prevent stagnating water. ProRep also produces a Drainage Medium, and other versions exist, usually in the form of clay balls. Essentially the drainage medium needs to create large pockets in which water can gather. It needs to be separated from the primary substrate on top by using a permeable mesh or felt layer.

This is an example of a bioactive setup using ProRep Bio Life. Many other brands for exotic pets make suitable bioactive-friendly soil substrates, so there is plenty of choice out there and combinations to make that will suit the animals in your paludarium best.

You can also get your selected plants in place. Going for native plants for your species is ideal, but not always practical. Similar species work fine as long as they are safe for your inhabitants. Plants may have some kind of pesticides on them if bought commercially, so keep them outside of the paludarium for a few days to be able to clean them up and prevent introducing these to your setup.

Vines, bromeliads, and other epiphytic plants work very well in tropical bioactives. Since there’s an aquatic environment involved, submerged and emerged plant species are also options. Airplants are great as they can be positioned in pretty much any spot in the canopy and generally need very little care to thrive.

Whatever plants you select, take into consideration their individual needs based on their natural habits. Bromeliads, for example, need a lot of sun and should be placed higher up towards the lighting without the possibility of becoming waterlogged. Some others may prefer more shade.

The Java Fern, Leptochilus pteropus, is a hardy and popular aquarium plant. It will happily grow completely or partially submerged.

Custodian invertebrates can also be introduced at this point. Choose humidity-tolerating species. A popular go-to are the dwarf white isopods, Trichorhina tomentosa, and springtails. More tropical invertebrates are available as options, including different colourful varieties of different isopods. You may be able to find species native to the same general locale as your herps, which would be more in line with the biotope!

Here is a brief list breaking down different types of isopods you could choose for your paludarium, which includes tropical, arid, and generalist species.

Custodians usually retreat into the substrate, particularly the dark humid areas. They will subsist on the plant and animal waste material available but may need some help while the environment is in its infancy. Springtail food is commercially available and will also feed other custodians, as well as small scraps of pesticide-free fruit and vegetables.

You can also top off the water to the maximum level now, or at least once the paludarium is in its designated spot.

TEST THE WATERS

The water needs to be ammonia-cycled before adding aquatic animals like fish or amphibians. Without doing this, waste can create toxic compounds in the water that makes the animals in it sick or worse. Resources are available online that explain how to do an ammonia cycle to prepare the water – you can use the same procedure as you would for a new, empty aquarium. Any reputable experienced person working with aquaria should be able to advise you on this if you are concerned – try your local trusted exotics shop.

In short, it allows beneficial bacteria to multiply that will break down ammonia and nitrites when animals are introduced and begin producing waste. The whole process can take anywhere from 2 to 8 weeks but is necessary for the success and health of the aquatic animals you want to keep.

Waiting for this period of time will also allow the invertebrates in the substrate to become well established. The plants will be able to become more secure via their roots – some reptiles and amphibians are notorious for uprooting their live plants. New lighting will also have a good ‘burning in’ period so they can reach a consistent output and you can resolve any issues.

Within this period, you should be able to assess how everything is placed in case of decoration issues, monitor temperatures and humidity patterns – then everything will be ready for your animals to comfortably settle in, without you having to make drastic changes that may stress them.

ADMIRE YOUR WORK; LEND A HELPING HAND

Once everything is running without issue, bioactive paludaria don’t take that much maintenance – certainly less than changing out paper towels day to day. Feeding your animals will of course still come down to you, as will any manual misting or operation of electronics – though many of these systems are programmable to be autonomous. For the first few weeks you should still remove droppings.

It takes a little while for bioactives to become reliably self-sustaining. Arboreal species are notorious for dirtying the glass, so some cleaning on your part will be required if you want a perfect view of the environment inside.

We would love to see your own bioactive enclosures and may even feature them in future here at EK. You can send us images on our social media platforms, as well as any questions you want answered for our Ask An Expert segment in Exotics Keeper Magazine.

After a while you may need to trim back your plants to prevent it getting too overgrown. There are ‘booster’ products available to add more nutrients to soil for plants that may be useful. Soil boosters and fertilisers produced specifically for bioactive vivaria will be safe for all the animals (some commercial fertilisers are toxic). There still aren’t as many processes happening in the paludarium as there would be in a larger natural environment, so some backup maintenance of the soil by using nutrient boosts every few months or even doing a partial soil refresh can be really helpful in keeping everything thriving long-term.

A commonly asked question is whether mushrooms are a good or a bad sign in a bioactive enclosure. The answer is: good! Mushrooms need nutrient rich environments to grow, so it is a good marker for your soil health. You can always remove them if you would prefer, but it won’t be long until they break down and become food for the invertebrates and soil bacteria.

That’s all the basics of paludaria covered. It’s always fascinating and exciting to see the world of exotic animal keeping evolve, especially in the direction of making captive environments more natural and enriching. To begin your journey into ‘advanced’ husbandry such as this, we recommend you join some advanced husbandry groups on social media – there are many that are bioactive-specific. Get engaged with the community and share your own successes. This way, in time, advanced practises such as this may even become the norm, which will benefit all the captive species we enjoy so much.