Table of Contents

How to Create a Bioactive Substrate

Table of Contents

Creating and Maintaining a Bioactive Substrate

Bioactive terrariums make for one of the most visually appealing reptile habitats, especially if they are done right. Further, they may create a healthier environment for your reptile or amphibian if the substrates are properly maintained. In this article, we discuss the most important aspects of a bioactive substrate, why they may promote better health in your pet, and how you can get started maintaining your own bioactive terrarium!

Likely the hardest part in getting started is a bioactive substrate.

What is a Bioactive Substrate?

A substrate is simply the material you use on the bottom of a terrarium or pet enclosure. This can be as simple as butcher paper. Really, anything to give your pet some traction and soak up their wastes is sufficient. 

Why is it called BioActive?

A bioactive substrate is much more complex but offers many benefits. It is called ‘bioactive’ because it contains many different living organisms. Most bioactive substrates contain bacteria, other microorganisms, and insects or worms. These organisms create a small ecosystem in the substrate, helping decompose your pet’s waste and leftover food products.

Bioactive substrates are usually species-specific but can range from substrates that mimic a tropic forest floor to substrates that mimic a dry scrubland environment. Most of the time, materials to assemble a bioactive substrate can be found at home improvement stores, around your home, and from plant nurseries. Some reptile stores and many online sources offer small insect “cleaning crews”, such as springtails or redworms, that can be added to the appropriate substrate to help decompose waste faster. 

Why Choose a Bioactive Substrate?

In general, there are two basic routes to go when setting up an enclosure for your pet. You can go the ‘sterile’ route, in which you use an easily replaceable substrate that can quickly and easily be cleaned or replaced when your pet makes a mess.

The sterile method is not new. Around 50-60 years ago, it became a very popular technique in zoos because it supposedly keeps animals from getting sick in more cramped conditions. And, the technique still thrives in many research laboratories today to house many animals at once. Authors of a scientific journal about amphibian care even note:

“Anurans (frogs) and salamanders often thrive in cages with moist paper as substrate, sections of plastic pipe as hiding places, and plastic aquarium plants as cover objects.”

So, you don’t necessarily need a bioactive substrate. Most reptiles can be kept with newspaper shreddings and plastic tubes. However, bioactive substrates do provide many benefits. This is why many zoos have switched to this more naturalistic route in their substrates.

Bioactive Substrates Look Better

First, bioactive substrates simply look better. Part of the reason modern zoos switched to the ‘second route’ of animal maintenance is that people like seeing animals in a more natural setting. Surprisingly, this method is not terribly expensive to set up and maintain.

Bioactive soils are easy to maintain

Second, bioactive soils are fairly easy to maintain. Because of the insect cleaning crews, much of the smallest food waste and animal feces is actively decomposed. While you should still spot clean the terrarium every day or so, it should be a much less intensive task. You may need to replenish the substrate with new materials if they become dried out or hard-packed. But, this may only occur after several months of use. 

Bioactive substrates promote natural behaviors

Third, naturalistic enclosures increase natural behaviors. As a wild animal, your pet still has many urges to burrow, hunt, smell, and taste the environment. In a more sterile environment, many of these behaviors may become stressful, repetitive behaviors because they cannot be expressed.

Benefit the MicroBiome

Lastly, a bioactive substrate may provide some benefits to your pet’s microbiome. The microbiome is all of the microorganisms your pet relies on to properly digest its food, and they maintain a delicate ecosystem in and on your pet. Living in a naturalistic setting with a bioactive substrate may help them maintain this delicate balance. 

How to Make a Bioactive Substrate

Wet Bioactive Substrates

While the exact moisture content will change depending on the species that you keep, most moist substrates can be created in a similar fashion. You essentially need two things: Soil and organic matter.

The soil should be very moist, as it will hold much of the moisture that your animal will need. Amphibians need this moisture for keeping their skin moist to absorb oxygen and maintain their water balance. While there are many different suggestions online for moisture content according to different species, most amphibians need soil that is moist enough to squeeze into a ball without the soil crumbling apart.

Tropical reptiles also need moisture to help shed their skin properly and minimize water loss from their lungs. However, depending on the species you have you may not want to add too much water. Some reptiles that come from drier habitats cannot handle the high moisture content and may develop respiratory diseases or other infections. 

Which Organic Matter Should I Use?

The second part, organic matter, can vary widely depending on the species you are trying to keep. If you are trying to replicate a rainforest, you may want to try dry leaves, peat moss, and coconut fibers. Other environments may need different components. Regardless, the purpose of the organic matter is to provide aeration, make the soil lighter, and hold nutrients for decomposers. 

Mix the wet soil with your wettened organic matter mix and fluff it up. You can then add detritivores like red worms, springtails, and other small insects that have evolved to eat small matter in the substrate. Then, place your substrate in the terrarium and you are ready to go! 

Dry Bioactive Substrates

Dry substrates are slightly harder to maintain in a bioactive state because not many insects and small decomposers exist in very dry environments. Further, natural environments like sand and rocks usually do not contain enough organic matter to maintain small decomposers. However, there are some options for desert terrariums and dry, scrubland-type terrariums. 

Which decomposers can I add to a Dry Bioactive Substrate?

Some of the only decomposers in these dry environments are beetles and millipedes. These insects can be added to an enclosure to make it bioactive. Some species of beetle and millipede are even specialized to live on animal waste in the desert. However, if you have an insectivorous pet you will have to provide plenty of hides and insure that the insects you use will not be harmful if your pet eats them. Some pet shops and online specialty stores provide these kinds of decomposers. 

How To Finish a Bioactive Terrarium

While the substrate is one of the most important aspects of any bioactive terrarium, there are several other additions you can make to really give your terrarium that naturalistic look. For many amphibians, a water feature is a great idea. If you make the water filter down through some moss, the bioactive organisms in the moss can help clean and treat the water.

Most well-developed terrariums also have species-specific plants that can encourage climbing, hunting, hiding, and basking behaviors. Live plants can sometimes be dangerous, so make sure you consult an expert before adding a plant to your terrarium. 

Last, but not least, don’t forget to maintain your terrarium in the appropriate heat and humidity range. This will not only help your pet survive, but it will help the microorganisms and insects in your substrate survive, reproduce, and continue their composting mission. This can be aided with the help of humidifiers, heat lamps, and regular bulbs with the appropriate light spectrum output.