Hey there! I’m trying to make a bioactive enclosure for my leopard gecko and I was wondering about substrate. People say eco earth (any loose substrate) is bad so what do I put the plants/cleanup crew in? Also if you feed your gecko out of their tank is eco earth ok?
Eco earth (coco fiber) is a poor choice for leopard geckos for several reasons.
Leopard geckos are from arid environments. Their humidity should be under 40%. Eco Earth retains moisture really well; that’s why it’s a good choice in a substrate mix for animals from humid, tropical areas. For leopard geckos it can cause problems with too-high humidity and condensation.
Secondly, coco fiber is very dusty when kept dry (as leopard geckos should be kept). This can cause breathing issues for the leopard gecko.Â
Finally, it is an impaction risk. Coco fiber is not “dirt”, it is fibrous material from the shells of coconuts. Leopard geckos can’t digest this, and it can get all tangled up in their digestive system. Since leopard geckos “lick” to explore their environment, they can be taking up small bits of Eco Earth even if they aren’t feeding in the enclosure.
Even if you feed your gecko outside of the tank, it’s not a good choice of substrate for these reasons.Â
For a bioactive substrate for a leo, there are other choices that are much better!
Arid bioactive enclosures are much harder than humid ones. I personally spent a couple years practicing with humid bioactive before setting up my leopard gecko in his arid setup. I wanted to make sure I knew what I was doing first. If you do choose to do an arid bioactive, be sure you’re first well versed in general leopard gecko care (keeping the temperature, humidity, and other parameters in the right place, feeding a nutritious diet, etc.), and if possible, practice with other humid bioactive enclosures first (even if it’s just for your feeder insects).
There are several reasons arid bioactives are more difficult:
The substrate is harder to get right. There are many different mixes and products that work for humid setups, but for an arid bioactive there aren’t many good mixes on the market, and you’ll probably have to make your own. The substrate must hold burrows, without holding too much humidity, and not become compacted or hard, or too dusty, when dry.Â
In addition, if your bioactive is planted, the substrate must support plant growth. For plants from arid environments, this typically means a fast draining substrate with some aeration around the roots. The substrate must also be deep enough to support healthy root growth.
My mix is organic top soil (this is purchased from a home improvement store and is labeled top soil -- it is NOT garden or potting soil), decomposed granite, and sand. The proportions of the mix will vary depending on the source of your ingredients and their make-up. Other mixes that work for arid bioactives may include other kinds of safe, organic soil, and clay like Excavator Clay.Â
On top of this I have a layer of leaf litter (live oak, magnolia, and trident maple). This helps keep any moisture in the substrate from raising the ambient humidity, provides hiding places, food, and humid refuges for the CUC, and prevents my gecko from licking the substrate too much.
I don’t think leopard geckos should be kept on any single-ingredient loose substrate. This includes “all sand”, “all coco fiber”, “all top soil”, or any others. In addition, plants will do poorly in any of these alone. You must create a proper mix that has all the necessary characteristics.
I also recommend against Calci-Sand (Repti-Sand, Calcium Sand, etc.) in any way, shape, or form for any animal.
Fewer species used as clean up crew do well in arid setups.Â
Most isopods need higher humidity than an arid setup will allow. There are a couple common species I recommend, such as Giant Canyon Isopods and Powder Blue Isopods. Common CUC species like white dwarfs and rough isopods typically don’t reproduce vigorously in an arid setup, and may simply die off.Â
I also recommend lesser mealworms/buffalo worms, which are harder to get than many CUC species. Regular sized mealworm beetles are more likely to become leopard gecko snacks, and are not very nutritious.Â
Springtails, which are the backbone of humid bioactives, typically won’t survive in an enclosure at under 40% humidity. If they do, it will only be in isolated pockets, and they won’t wander out into the desert of the enclosure in search of things to eat.Â
You’ll need to create multiple humid refuges for the CUC throughout the enclosure, so that the CUC have ways to travel around the enclosure doing their job. This can be accomplished by creating a slightly more water-retentive mix, such as some of your arid mix with coco fiber mixed in, or a ball of sphagnum moss. This can be placed at strategic areas around the enclosure, in small fist-sized amounts. These humid refuges need to be covered (such as with driftwood or cork bark) so that they don’t raise the ambient humidity too much, and so that they aren’t creating a dangerous wet area in the enclosure that might lead to health problems for your leopard gecko. I differentiate these from my gecko’s humid hide in that they are securely covered by flat cork pieces, palm bark, rocks, and otherwise inaccessible to my gecko, but not the CUC.Â
Some people choose to put a moisture-retaining substrate layer on the bottom with the drier, fast draining mix on top, extending the moisture-retaining substrate up the corners so the CUC can access it. However, I don’t think this is the best choice in the case of a leopard gecko enclosure. For one thing, not all CUC species burrow, and those that do don’t necessarily burrow deeply enough that they’d reach the lower layer of substrate. In addition, the CUC may not venture away from those corners, which is why I instead prefer to scatter the humid refuges around so that they have access to all the enclosure to do their jobs. Finally, a lot of plants from arid locations do not like having their feet constantly wet, as a moisture-retaining substrate would do.
Loose substrates, including mixes used in bioactive, are an impaction risk. I am a big proponent of bioactive -- all my reptiles and most of my bugs are in bioactive enclosures. However, I don’t think the fact that it can be more risky than solid substrate (like tile) should be ignored. Bioactive enclosures should not be used for new animals, which should be on paper in quarantine, or animals with health problems (acute or chronic). In addition, if your parameters, such as heat or humidity, are off, loose substrate is more dangerous. A properly designed substrate mix is less dangerous than many single-ingredient loose substrates like sand alone or coco fiber alone, but they are still more of an impaction risk than tile.
Eco Earth has its place in leopard gecko care, just not as a substrate. Some people mix it about 1:1 with sand, keep it very slightly damp, and offer it as a digging box in an enclosure with an otherwise solid substrate. As long as it is in a mostly enclosed plastic box with a small hole in the lid to climb in, this won’t raise the ambient humidity of the enclosure much. The sand/coco fiber mix is pretty good at holding burrows, and keeping it very slightly moist keeps it from getting too dusty. Coco fiber can also be used in a humid hide, which, again, is mostly enclosed so the humidity is trapped inside the hide (where you need it!). However, it is not a great choice as a substrate for leos, and won’t work on its own as a bioactive substrate.
