How to Increase Humidity in a Terrarium

How to Increase Humidity in a Terrarium

Whether you live in an arid climate or you care for a species that requires a high level of humidity (such as a rainbow boa or amphibian species), you’ll certainly need to know how to increase humidity in a terrarium!


How to Increase Humidity in a Terrarium

Sphagnum Moss is one of the best, natural ways you can increase your humidity levels.

Humidity vs Relative Humidity

Before we go any further it is important we understand what we are talking about!

Humidity: as you probably know is the term we use to describe the amount of water vapor in the air.

Relative Humidity: on the other hand, is the actual measurement of the amount of vapor in the air represented as a percentage of the amount needed to fully saturate the air at its current temperature.

Relative humidity is what you are working with when discussing humidity levels inside your terrarium. The reason it is “relative” is due to the fact that air is capable of holding different amounts of water vapor at different temperatures.

Warm air can hold more moisture than cool air as shown in this image below.

How to Increase Humidity in a Terrarium

An equal volume of water vapor will result in different levels of relative humidity at different temperatures. Therefore it is important that you are trying to balance your reptile’s humidity levels after you have established the proper temperature parameters.

If you are looking for how to increase humidity in a terrarium… then here are the first two keys takeaways:

  1. Higher relative humidity will require more water vapor in the air
  2. You must ensure your temperatures are set properly for the species you care for before trying to establish proper humidity levels.

How to Measure: Best Hygrometer for Reptiles

Okay, so I understand what relative humidity is but how do you measure it? What is the best hygrometer for reptiles?

There are many digital hygrometers on the market, typically you can save money by buying one off of Amazon rather than your local pet store.

You have two options when it comes to hygrometers:

  1. Inexpensive ($3-8), the two below are the ones I use (the white one seems to be more accurate, see below).Inexpensive hygrometers have two fairly serious faults. The first is that they are typically not that accurate and the second is over time they will become even more inaccurate as extended exposure to high humidity tends to damage the sensors.
    Best reptile hygrometer- DC103
    Best reptile hygrometer- DC103
    Best reptile hygrometer
    Best reptile – Brand: Amir


  2. Or expensive ($10-25). You’ll find high-quality hygrometers in the cigar hobby. Those guys are serious about there relative humidity! Cigar hygrometers are very accurate, can handle high humidity for a very long time and can be calibrated and recalibrated to maintain accuracy.
Best Reptile Hygrometer- Hydroset II
Best Reptile Hygrometer- Hydroset II


Best reptile hygrometer- Cigar Oasis Caliber IV
Best reptile hygrometer- Cigar Oasis Caliber IV


If Cheap Hygrometers are Inaccurate, Are they even worth it?

You don’t feel like spending the extra money on an expensive, more accurate hygrometer hey? I don’t blame you! I didn’t either. Fortunately, there is a way you can calibrate even the cheap units!

Calibrating a Hygrometer

How to Test a Hygrometer: 6 Steps (with Pictures) – wikiHow

Instead of a ziplock bag, I used a Tupperware container like in this video:

Note: You need to wait the full 24 hours, as the video says. Not 6 like the wikiHow article says.

Your inexpensive hygrometer will not have a button to adjust the reading it gives you so it is just something you’ll have to keep in mind. For example, this was my result after calibrating my units:

Best Reptile Hygrometer
Best Reptile Hygrometer

This meant that the white hygrometer bang on but the black ones seem to read about 10-12 % high. There is nothing I can do to the black ones to make them display an accurate figure, instead, I just have to do some mental math every time I look at them.

NOTE: I redid this calibration about 1 year later and the white one then displayed 72% (i.e. 3 % low) and the black ones displayed 79% (4% high). As I said above, over time the inexpensive hygrometers will fluctuate in their accuracy.

How to Increase Humidity in a Terrarium

There are several different ways you can increase humidity in your animal’s terrarium. Your goal should be to set your enclosure up in a way that the relative humidity stays within your animal’s requirements with little to no regular intervention.

In other words, you should not be fighting with your humidity levels on a regular basis. Things should be set up in a way that your humidity natural sits in the healthy range for your specific animal.

How to Increase Humidity in a Terrarium: Various Methods


The more ventilation you have the lower you relative humidity will be. If you have an animal that requires high levels of humidity than limited ventilation is in order.

My Brazilian Rainbow Boa enclosure only has eight vent holes, four of them are shown below:

Brazilian Rainbow Boa Ventilation- How to increase humidity in a terrarium
Brazilian Rainbow Boa Ventilation- How to increase humidity in a terrarium

Water Dish:

This one is pretty straightforward! The larger the surface area of your water dish, the more evaporation, the more water vapor in the air of your terrarium. Some people like to but their water dish on the warm side of the enclosure to illicit more evaporation. In my opinion that encourages bacteria growth in the water dish.

I like to use large plastic containers for my water dishes (without the lid obviously):

Large water dish- How to increase humidity in a terrarium
Large water dish- How to increase humidity in a terrarium


There are many types of substrates you can use to help maintain humidity in your terrarium. Cypress mulch and EcoEarthare my favorites, you can read more about that in this article: Best Ball Python Substrate.

Cypress Mulch- How to increase humidity in a terrarium
Cypress Mulch- How to increase humidity in a terrarium
EcoEarth- How to Increase Humidity in a Terrarium
EcoEarth- How to Increase Humidity in a Terrarium

These are great substrates but keep in mind there affects on your terrarium’s humidity is not permanent. They will slowly dry out over time and no longer provide as much moisture as they did right out of the bag.


Misting your terrarium is one of those controversial methods! Many people say you should not use misting as a way to maintain humidity (unless of course, you are using it for your animal’s drinking water).

Generally, people say to avoid this method for two reasons: 1) it implies that you have not done a great job setting up your enclosure so it can maintain proper humidity on its own and 2) it can lead to too much sitting-water in the terrarium.

Exo Terra Mister- How to Increase Humidity in a Terrarium
Exo Terra Mister- How to Increase Humidity in a Terrarium

“Anti-misters” definitely have a point! This is a method that should be used sparingly but I do think it has its place provided it is done properly. If you are like me and have to deal with an extremely arid climate then misting may be a necessity for you on occasion.

When I mist, I make sure to mix around the substrate while I do it. I am looking to create a slightly moistened substrate and that is it, not sopping wet!

Sphagnum moss for Snakes and other Critters!

Just recently I tried out sphagnum moss by Zoomed and loved it! It is a very easy (and reusable) product that holds moisture for a very long period of time! I added it to my Brazilian rainbow enclosure and it maintained a relative humidity of over 90% for more than 2 weeks straight without having to be re-moistened.

How to Increase Humidity in a Terrarium

I highly recommend this product if you are needing a boost in your humidity levels. Watch my full video review below:


Crested Gecko Cage: Here are 3 Awesome Options!

1: Who Am I?

Crested Gecko Cage: What are the Options?

So you are looking into getting a crested gecko? Awesome!

Crested geckos are a fantastic choice, especially if you are new to the hobby. In this article,  am not going to cover specific crested gecko care, instead, I want to focus your choices for a crested gecko cage!

Crested Gecko Cage
Crested Gecko Cage
NOTE: I will only be discussing crested gecko cage options intended for housing a single gecko. In my opinion housing, more than one gecko together is asking for problems down the road. Unless, of course, you are planning to breed… in which case I can offer no advice as I have not ventured down that branch of the hobby.

A few things to keep in mind:

  • Crested geckos are arboreal, their terrariums should be tall rather than wide
  • The minimum crested gecko cage size is 12″ x 12″ x 18″ although I believe a full grow adult should be kept in something at least 18″x 18″ x 24″.
  • Provide lots of horizontal perches to avoid floppy tail syndrome
Crested Gecko Cage: Here are 3 Awesome Options!
Horizontal Climbing Branches- crested gecko cage

Types of Crested Gecko Cages:

Store Bought Terrariums

Store bought terrariums are really a great option! There are two main brands: Exo-Terra and Zoo Med. Both brands carry terrariums with dimensions 12″ x 12″ x 18″ and a 18″ x 18″ x 24″ (L x W x H), which are typical dimensions for young and adult crested geckos. Click on the pictures to learn more about each one.

Crested Gecko Cage: Here are 3 Awesome Options!

Crested Gecko Cage: Here are 3 Awesome Options!

These terrariums are great, they are ready to go out of the box and designed for exactly what you need. They have ample ventilation, a bottom glass tray to hold substrate, and front opening doors for easy access (the doors are equipped with a simple locking mechanism as well).

Many of them are sold as “starter kits” as well so they will include a nice background and usually some decor.

These terrariums will be your most expensive option for your crested gecko cage but the price is more than worth the quality. I have used the same Exo-Terra terrarium FOR OVER A DECADE and it’s in the same space as when I bought it!

Before going to your local pet store just out the prices on Amazon first! I have noticed Amazon is usually cheaper than chain pet stores ESPECIALLY if you have Amazon Prime (how can you beat FREE shipping?). Quite often you’ll find small pet stores using Amazon to liquidate extra stock… that’s where you’ll find the best deals.


I only have experience with the Exo-Terra models but I believe there is very little difference. Although one definite difference to keep in mind is the Zoo Med terrariums come with one door and the Exo-Terra terrariums have two doors… french door style. I prefer the two door system because it is allows you to only have a portion of the cage open at once.

Upright Aquarium

If you are someone who would like to save some cash you can use a modified aquarium! The key word there is MODIFIED’, a aquarium setup in its typical “fish tank” orientation  is an unacceptable setup for a crested gecko cage. Remember, your crested gecko cage needs to be tall, not long.

Crested Gecko Cage: Here are 3 Awesome Options!

You can usually find cheap aquariums on your local classifieds. You’ll want to look for:

  • A 10 Gallon Tank for juveniles
  • A 20 Gallon Long Tank for Adults

Once you find an acceptable aquarium (If you bought it second hand, I think it goes without saying… give it a GOOD cleaning), you have two good options to convert it to a terrarium.

The first is the simplest and that is to stand the tank up in an upright position (in its tallest orientation) and purchase a screen cover that fits the correct dimensions of your tank (click the picture to learn more):

Crested Gecko Cage: Here are 3 Awesome Options!


The second options is more hands on. There are plenty of YouTube videos explaining how to convert an aquarium into a terrarium but SepraDesign probably does the most thorough job:

DIY Crested Gecko Cage

The third option for a crested gecko cage is to Do-It-Yourself!  Now there are many different ways this can be done. I will share two that I have used (for different species) that would work quite well for crested geckos.

The first is converting a piece of furniture or a display cabinet into a terrarium. You can find that article HERE and the video below:

The second is using old plate glass to build your own terrarium and then proceed with a similar method as SepraDesgin used to convert and aquarium into a terrarium. That article is HERE and the video is below (if I had built this for a crested gecko I would have built it in a vertical orientation):

At the end of the day you should choose the option that works best for you. As a goal you should try and include as much natural enrichment in the enclosure as you can safely maintain.

Live plants, real-natural substrate (over paper towel, etc.) and climbing branches are a great way to enrich your crested gecko cage.

Crested Gecko Cage: Here are 3 Awesome Options!
Live Plants- Crested Gecko Cage

If you are looking to add real climbing branches from outside, please read THIS ARTICLE or watch the video below: