All About Bioactive Reservoirs | Current problem

Herpetoculture is a field that (correctly) resembles evolution rather than fashion. When people ask me “What’s up?” across the counter, I rarely have much to say other than a new color form of this or a new subspecies of that. Things are slowly changing in our part of the pet world…but they are changing.

Over the past few years, my clientele and the industry in general have been abuzz about bioactive reservoirs. Honestly, for European enthusiasts, it’s the essence of “old hat” (they’ve been at it for decades), but for our customers, it’s new.

What is a bioactive reservoir?

Bioactive tanks are defined as enclosures that use a combination of plants and live animals to achieve a more balanced and attractive vivarium that, in theory, will also be more maintenance-free, using microfauna to consume animal waste . The trend started with dart frog keepers whose charges required live plants as colonies for frog eggs and tadpoles, but it has been adapted to a much wider range of pets.

I now get people asking to set up bioactive tanks for columbia boas, sulcatta tortoises and bearded dragons, and I have to let them down gently; there are many animals for which the bioactive reservoir is, at least at this stage, not really a feasible option.

Here’s why. This type of cage requires microfauna and flora which themselves require high humidity, mild or low heat and a little disturbed substrate. Most of the smaller invertebrates that run a bioactive tank have gills, which makes them totally unsuitable for a desert situation. Moreover, it is very difficult to establish even the hardiest desert plants in the confined and often bottom-based heating systems for desert reptiles.

Some people try using dermestid beetles in their desert terrariums, and it might work for something like a bearded dragon, but they really can’t keep up with the amount of waste a tortoise or boa might produce. , and so they don’t really affect a keeper’s need to clean a cage by hand. While it is possible (with some difficulty and unwieldy upkeep) to establish a bioactive reservoir in the desert, for the purposes of this article I will focus on the “wet” bioactive reservoir.

So which animals do well with bioactivity? Well, most frogs and other amphibians will do just fine. So will temperate and tree-dwelling lizards like many chameleons, geckos and anoles. Even some small temperate snakes will work.

Find the best fit

Now, where to start? With the enclosure itself, of course. I prefer the look and durability of glass tanks, although some people use acrylic tanks for animals that are unlikely to scratch the sides. In recent years, Exoterra and Zoo Med have significantly expanded their tank lines to include pallidariums (designed to incorporate aquatic features) and leaded tanks.

Remember that when choosing a tank you will need to provide a screened top capable of withstanding UV fluorescent light the full length of the cage. Even if animals don’t need it, plants will. Bioactive tanks are by nature more spacious than the animals themselves need. While a 10 gallon. tank might be perfectly adequate for a few green frogs, those same frogs will probably require a 30 gallon. or more to also support the auxiliary plant and animal life in which you are trying to balance.

It is essential that when choosing a tank, you also decide which animal or animals will inhabit the space. To some degree you may change your mind once the tank is established, but if you decide to make a tank for dart frogs, but at the last minute change to crested geckos, your indecision will either result in unhappy animals or unhappy you.

Once you have the tank, it is crucial that you develop a plan for how you want your system laid out. You not only have to plumb it with filters etc. (assuming you have a water section), but, even without a water feature, you’ll need to figure out where to place your substrate, plantings, and cage furniture (logs, hides, rocks, and such). This is where you can start getting creative and imaginative, and it can really be fun and exciting to design and execute. You can improvise on the details, but have a solid design.

Work on substrates

You have your base cage set up and the cage furniture figured out and placed. As you do this you will also need to work on substrates. In particularly wet setups, I recommend a bottom layer of coarse gravel, clay granules and charcoal, over which you can use a good organic topsoil supplemented with a number of additives: peat, bark of orchid, sand, etc. I really like cypress mulch, which tends to resist mold and rot. Many people like cocoa fiber, but I find that it tends to “rise” on the glass and look messy.

There are a number of great substrates on the market right now designed for different styles of tanks (desert, rainforest, forest, etc.) and we particularly like the very specifically blended soil bags from Bioactive Supply. In my experience, nothing helps sales like getting customers past the question “Do I need?” directly to the question ‘What do I need?’ question.

There are also substrate additives on the market that will introduce microflora and fauna to your soils. These include the necessary bacteria and fungi. Hagen, among other things, makes an excellent soil additive that will establish those useful populations for your media.

pick plants

Once you’ve laid out the basic tank, things get even more fun, because plant selection is the next step. I learned something from a professional gardener friend: planting is always a kind of experience. Which plants will work which particular in the tank is a bit of a dice game; eventually this reservoir will teach you what works where. Be aware of your UV lighting and the direct heat you provide to your animals. Most plants absolutely need the first and wilt under the second.

Above your substrate and plants you will want to supplement with a layer of leaf litter. This will help retain underlying moisture and help feed the microfauna you are about to introduce. Again, various clean and safe leaf litters are on the market, although it is reasonably easy in most parts of America to simply go out and carefully pick up the oak leaves. (I’ve never ceased to marvel at the willingness of customers to buy dirt, sticks and stones from us, so I guess I shouldn’t be surprised that this extends to fallen leaves too!)

And now, the last step before we introduce the pet: what we in the industry like to call the cleanup crew (fancy name: scavenger). These are isopods (a fancy name for woodlice), springtails, woodlice and earthworms. This is, ultimately, what the bioactive reservoir is. They are there to consume your current pet’s waste. They are the final element in the balancing act that we call the bioactive reservoir.

We have a local breeder who owns a slew of isopod variants with colorful exoskeletons and adorable names that has earned their own set of collectors, breeders, and hobbyists. With a little research, you can find one too, or maybe start raising them yourself! Some of them command amazing prices and it shows… you never know what the next big trend will be! PB

Owen Maercks has enjoyed being immersed in the world of professional herpetoculture for almost 40 years. His store, the East Bay Vivarium in Berkeley, California, is one of the oldest and largest herptile specialty stores in the United States.