TThe Bio Dude | Your #1 shop for all things reptile! | Spend $150 get $8.95 Flat Rate Shipping | Current order processing time: 3 business days | NOTICE: We currently cannot ship live plants to California

Fungi in Bioactive Setups: Should You Be Worried? 🍄

Fungi in Bioactive Setups: Should You Be Worried? 🍄

So you’ve found a mushroom in your vivarium. In a world that generally considers fungi unsightly, dirty, and even dangerous, the appearance of anything fungus-y in a bioactive setup can be alarming. Just because it’s alarming, however, doesn’t necessarily mean that it’s bad. Here’s what you need to know about fungi in your bioactive terrarium:

Benefits of Fungi in Your Bioactive Setup

In nature, fungi play important roles in the complex harmony of an ecosystem. Mycorrhizal fungi form beneficial relationships with plant roots, improving the plants’ health by increasing their ability to absorb water and nutrients. Fungi also help decompose dead wood, leaf litter, and other organic wastes to return nutrients to the soil. Their fruiting bodies also provide a food source for many organisms, especially microfauna like springtails.

The goal of a vivarium is to create a miniature ecosystem, so if you want a healthy vivarium, you’re going to have to get comfortable with having some fungi in there. After you’ve set up a new bioactive, especially if you inoculated the soil with Bio Shot, don’t be surprised to see a CUC population boom in the first two months or so. During this time, both fungi and microfauna get excited about all of the biodegradables (food) that they find themselves surrounded by. This also means you might suddenly see a lot of mushrooms and even some mold. This is all an expected and essential part of getting your viv properly cycled in preparation for long-term functionality as its own ecosystem (if you’ve kept an aquarium, “cycling” is likely already a familiar concept to you). This is also why it’s important to wait a bit after setting up a new bioactive before introducing your pet.

Over time, your plants and CUC will figure out a balance and things won’t be quite so crazy anymore.

Problems to Look Out For

Of course, it’s not all sunshine and roses. Some fungi are harmful, and too much fungus or mold can be a warning sign of imbalance within your vivarium.

Chytrid fungus, snake fungus, and yellow fungus can be extremely harmful to some reptiles and amphibians, so you want to avoid introducing them to your viv at all costs. Fortunately, this can be avoided by properly quarantining your pet after purchase and being very careful about the places you harvest branches and biodegradables from and the way you treat them before adding them to your viv. Infectious plant fungi can also threaten the health of your plants, causing them to become discolored and/or drop leaves. Depending on the fungus, you may be able to treat it or you may have to replace the plant. Properly cleaning and quarantining plants helps prevent plant fungus from popping up in your vivarium, as well as making sure your enclosure has good airflow — especially if you’re using an automatic misting system.

When mushrooms or mold do show up, keep a close eye on them. In a healthy viv, your springtails and isopods should respond quickly to feast on it if it’s within reach. If you notice a suspicious absence of CUC, that likely means your populations have become depleted for some reason. This means it’s time to top up your CUC and make sure that you’re providing enough humid refuges, biodegradables, and additional food like Bug Grub and Springtail Grub to maintain them.

If you’re seeing a LOT of mold in your viv, it means that your setup is either too wet or you have something that is actively and rapidly breaking down. Grape wood is a common culprit for mold in tropical setups, as it’s not well suited to a humid environment. While mushrooms are rarely cause for concern in vivariums, mold can be, so it’s best to remove any décor items with a lot of mold on them. Adjusting your misting and/or watering schedule and improving airflow in the enclosure will also help keep mold in check.

For a list of specific molds and fungi common to bioactive setups and what to do about them, read our article: Understanding Fungal Growth in Bioactive Terrariums and How to Address It.


To sum it up, most fungi are beneficial in bioactive setups and won’t harm your pet, although you do need to look out for symptoms of fungal disease in plants and animals, which are caused by fungi not visible to the naked eye. Mold is generally harmless in small doses, but too much of it often indicates a problem in the balance of your vivarium’s “ecosystem.”

To help keep your vivarium in balance, ensure good airflow, make sure your substrate drains well, and don’t let things get too wet. Aside from promoting balance, your plants and pet(s) will also be healthier for it! But generally speaking, mushrooms aren’t really something to be worried about. They’re just a natural part of recreating nature, and they’re often quite interesting to look at!


Image by Stefan Schweihofer from Pixabay

Previous Post Next Post

  • Rebekah Walenta


Access Denied

What a shame ----  you do not have permission to view this page : D