How To Prevent Mold In A Terrarium

Nick Durante
by Nick Durante
Credit: Shutterstock / Dirk Ercken

The sight of mold in a terrarium is enough to make anyone enter crisis mode. While it is inconvenient, it doesn’t mean that your terrarium is in grave danger. However, you should still take several steps to prevent mold in your terrarium.

You can prevent mold in a terrarium if you use activated charcoal and put springtails in the enclosure. Springtails target and eat mold spores, and other bugs, like isopods, eat dead plant matter to reduce the risk of mold. Add peat moss to your substrate and air your terrarium out for a few hours every 2-3 weeks to remove excess moisture.

It’s also a good idea to put a fan in your terrarium if excess moisture is a consistent problem. Follow along as we explore how to prevent mold in a terrarium.

Why Is There Mold In My Terrarium?

Mold forms in terrariums because of excessive moisture and poor airflow. You can also accidentally introduce mold to your terrarium via contaminated rocks, plants, and decorations from a pet store. Mold is especially common in dark, stagnant terrariums that don’t get enough attention.

How To Stop Mold From Growing In A Terrarium

1. Use Activated Charcoal

Activated charcoal is one of the best-kept secrets, although seasoned terrarium hobbyists have recommended it for years. This simple remedy can help prevent mold in a terrarium and rid it of toxins. That said, you must replace the activated charcoal in your terrarium roughly every 6-8 months for the best results.

The anti-mold effects of activated charcoal eventually wear off, but it’s easy to find more. Spread the charcoal on the rocks and substrate in your terrarium. Remember to wear gloves, as activated charcoal is quite messy and can make your hands dirty.

2. Introduce Springtails

Springtails act as superheroes in terrariums. Not only do they eat harmful bacteria in terrariums, but they also eat mold. They even find and eat fungal spores, and that helps stop mold from spreading throughout the enclosure.

Springtails also enrich the substrate with nutrients to create a self-sustaining environment. It’s easy to find live springtail cultures, and they require no maintenance. Simply leave the springtails alone once you introduce them to your terrarium, and they will do all the work.

3. Wash Plants Before You Put Them In Your Terrarium

While many plant nurseries are trustworthy, some plants contain harmful bacteria and fungal spores. This makes it easy to unknowingly create the perfect conditions for mold to grow in your terrarium. Carefully rinse each plant and gently scrub the leaves before you put it in your terrarium.

This will also help keep snails and other pests out of your terrarium. That said, you must make sure the plants are not soaking wet when you put them in the enclosure. Otherwise, the excessive moisture may contribute to mold and mildew.

4. Use Peat Moss

Peat moss is not only great for your terrarium’s substrate, but it also helps prevent mold growth. The low-pH nature of peat moss makes it hard for mold and mildew to grow. It also helps protect against root rot, which is a common problem in terrariums with excessive moisture.

You can have great results with a 1:1 ratio of potting soil and peat moss. Peat moss isn’t an ironclad miracle cure for mold, but it can reduce the risk and slow growth.

5. Chamomile

Not only is chamomile delicious, but it is also anti-fungal. Granted, it’s not as strong as store-bought fungicides, but it can help get rid of mold. Steep some chamomile tea in a spray bottle and spray the glass in your terrarium.

It doesn’t take too much, so there’s no need to oversaturate your terrarium. Chamomile contains sulfur, and it’s strong enough to kill mold spores. This can help kill existing mold and prevent mold from growing later on.

6. Apply Hydrogen Peroxide

It’s no secret that hydrogen peroxide is strong enough to kill viruses and bacteria. Luckily, it’s also strong enough to kill mold in your terrarium. You can prevent mold from spreading if you apply hydrogen peroxide to spores you find throughout the enclosure.

That said, you must be careful, as hydrogen peroxide can damage the plants and substrate in your terrarium. You can avoid that problem if you use a small amount of peroxide and precisely apply it with a cotton swab. Never pour hydrogen peroxide onto the substrate, glass, or rocks in your terrarium.

7. Use Distilled Water

Most people simply use tap water to mist their terrariums because it’s so convenient. That said, tap water can sometimes contain impurities, bacteria, and heavy metals that contribute to mold. It ultimately varies, depending on where you live, but you can avoid this risk if you use distilled water.

Water distillers are easy to use and more convenient than continually buying distilled water. Distill a big batch of water at once, put a cap on it, and store it for later use. The process is quick, and you’ll have healthy water for your terrarium.

8. Air Out Your Terrarium

Many people keep their terrariums closed the majority of the time, and that’s often fine. However, you also run the risk of excessive moisture retention, which makes it easy for mold to grow. Ideally, you should air out your terrarium every 2-3 weeks for a few hours to remove excess moisture.

This especially comes in handy if you accidentally overwater the substrate. You don’t need to remove the lid entirely, but at least open it slightly. It’s still a great idea to manually remove mold spores with hydrogen peroxide. After that, the lack of excessive moisture will stop mold from forming in the future.

9. Use A Fan

You can’t go wrong with a terrarium fan if you have a big enclosure. They effectively increase air circulation to remove excess moisture from a terrarium. The constant airflow makes it hard for mold to grow in the enclosure.

That said, large fans may remove too much moisture, and that makes terrariums less sustainable. Adjustable fans are the best option because you can make sure the enclosure still retains moisture. Your terrarium should stay healthy as long as some condensation still forms on the glass.

10. Keep Your Terrarium Clean

Terrarium maintenance is essential, and it can help prevent mold from growing. Fungal spores love dead plant matter, and terrariums typically have lots of it. That’s unavoidable, as parts of the plants in your terrarium eventually fall off and decay. This makes it easy for mold to grow, so you must regularly remove the dead plant matter.

You can save yourself some time if you introduce isopods and millipedes to your terrarium. These small bugs love to eat dead plant matter, and that helps reduce the risk of mold. You must still clean the glass and manually remove some dead leaves occasionally, but the bugs will do the rest.

Summing It Up

Air out your terrarium every 2-3 weeks for a few hours and add activated charcoal to the enclosure to prevent mold. Bugs like springtails can naturally remove mold, as they eat the spores in a terrarium. Spray the glass and mold spores with chamomile and regularly remove dead leaves to prevent mold growth.

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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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