There is a misconception that placing some plants, some soil, and a clean-up crew in with your reptile or amphibian, and hey presto you have a bioactive vivarium. Sadly it's not that easy.
What is a bioactive vivarium?
A simple definition of bioactive is that it has an effect on a living organism. But the term as we use it means that there is an entire ecosystem in the vivarium, allowing waste to be broken down and the resulting nutrients to be used by other inhabitants of the vivarium, for example, plants, insects, and yes isopods.
In practice, you will need to do some cleaning, and it will take months, if not years for it all to balance out. It's also advisable to replace substrate periodically, a section at a time, and if you have a drainage layer, make sure it doesn't go stagnant. But despite all that, it’s worth it. You will be providing your inhabitants with all the extra things that might be missing from their diet, surroundings, and so much more.
The three layers of bioactivity
Substrate
This is the foundation of your ecosystem, and there are no two ecosystems with the same base. A bit of research here can pay dividends down the line. Soil can retain moisture helping with humidity. Different plants need different soil types and structures, and different viv inhabitants will also want different things.
Topsoil is a great place to start. Make sure it's organic, or homegrown as chemicals in the soil can cause issues for years.
Now you need to look at the amount of moisture you want to be held, and the natural substrate in the wild. A beardie lives on sandy soil, even in the more humid microclimates, whilst something native to a rainforest floor will have a heavy organic layer and need a lot higher humidity.
Most isopods need relatively high humidity, and there are a variety of things you can add to the soil to increase the water retention properties.
Which brings us to our first tip. Leaf litter as well as being a great foodstuff for isopods, will also increase the amount of water retaining properties. Add in the nutrients that plants need, and you don't even need to mix it in. As long as you have something that will help the leaves decompose. For example, isopods, then you can just put a layer over the soil and let them do their thing.
Bioactive soil
There is very little that can make soil bioactive other than time. Generally, it's the fungi, bacteria and other microorganisms that make a soil bioactive.
So for our second tip here is a way to increase the amount of these microorganisms. Use a variety of plants. Plant roots are teeming with all these essential life forms. Plants that have been grown in soil, and organically will have more than those grown hydroponically, or in intensive setups. So to take things a step further see if you can find plants that have been grown in a small nursery, or even by an enthusiast in their own home. Check your local marketplace to see what's available.
Plants
There are a huge range of plants out there, many will be native to the area your vivarium inhabitants are originally from. But many will be too big for the size of the enclosure.
So third tip, you can plant something that is going to grow too big, with the intention of moving it out of the viv as a houseplant later, and then take cuttings from the original plant to keep in the viv.
For high-humidity vivariums, it's well worth remembering that most aquatic plants are in fact only semi-aquatic, and are grown out of water with only their roots wet. In fact, a fair number of plants that are sold as aquatic are only able to survive underwater for a few months.
This means there are a huge number of plants that you can add to your set-up, they're normally smaller than many house plants, relatively cheap, and available at many fish stores. They're also not treated with chemicals in most cases, just ask for plants that are shrimp-safe.
If they have upright stems and the plant can stand up out of water it is suitable for a high-humidity vivarium.
Clean up crew
We're clearly biased, but all cleanup crews should be based around isopods. Maybe with some springtails, and the occasional suitable snail. There are a whole load of isopods that you can keep with something suitable for almost every enclosure you can think of, head over to our shop to see what we have in stock.