Crested Gecko Substrates

Next to feeding, the topic of substrates is the second most controversial subject in keeping crested geckos. There are certainly risks involved with substrate choices. Any type of particulate substrate (a bedding made of tiny pieces such as soil, sand, peat moss, coconut fiber, etc) can cause a health risk to your gecko – causing eye and skin irritations, choking hazards and impaction in the gut if eaten; or being too moist or too dry and resulting complications.

The purpose of a substrate bedding in a crested gecko enclosure is to help control odors and aid with cleanup (your benefit) and to provide proper humidity and a retreat for thermoregulation if the gecko gets too hot or cold (gecko’s benefit). We feel that paper towel is probably the safest and easiest substrate initially, but that a naturalistic soil mix is best overall substrate for most crested geckos. The main exception to this are hatchlings and breeding females. Because there is a risk of any gecko eating a particulate substrate, we don’t recommend it for hatchlings and juveniles under 8 grams.

Avoid any “litter” made for small animals. Most of them are definite impaction risks or otherwise not suitable for crested geckos. Specialty reptile “sand” such as Calci-sand is absolutely not appropriate for cresties or any animal.

Not all non-particulate substrates are safe or beneficial. Reptile carpet can harbor bacteria and mold as well as catch gecko toes or teeth as they chase prey. Artificial mulch mats are an attractive option, but they do not absorb moisture or odors so routine weekly cleaning (or more often) is a must. The same goes for shelf liners. Replace often. Geckos have been known to tear off and eat paper towel strips, which caused intestinal issues & prolapse but eventually passed from the body with time. Butcher paper might be a better choice as it is less easy to tear.

You will need to research different options to find the one that best fits the needs of you and your gecko.

We favor a natural soil substrate that retains water but drains well. When set up properly with plants and small invertebrate cleaning crew, naturalistic enclosures are self-maintaining, with only spot-cleaning or scrubbing of furnishings needed a few times a year, and regular glass cleaning with vinegar & water to maintain good visibility of your tank.

Terrarium Soil Mix

Many online retailers offer soil mixes that are excellent for home terrarium use. They contain a mix of soils and dry botanical ingredients, such as tree fern fiber (made from the roots of Cyatheaceae fern species. True “soil” is not good for terrarium use because it tends to compact and become soggy. The Atlanta Botanical Gardens of Atlanta, GA created the “ABG Mix” to allow aeration and host beneficial microorganisms that mimic natural cycles. The specialty mixes contain blends useful to orchid growers as well as reptile & amphibian keepers. This is the preferred mix for the health and beauty of a crested gecko display tank.

If you have a lot of tanks to fill, it might not be economical to order all of your supplies online or buy them at a pet shop. You can find some good options at local gardening centers and hydroponics stores, if you know what to look for – and what to avoid. Start with a good organic potting soil, topsoil or compost that doesn’t have added perlite, vermiculite, or wetting agents. Next, get peat moss or coco fiber (coir) to add a little more body and aid moisture retention. These are referred to as “soil conditioners”. Mix in 10-20% of washed play sand – the kind you can find for children’s sandboxes – to give variety to the particle size to avoid compacted dirt. You can change this mix to suit the conditions of your tank. A small amount of sand works well for temperate & tropical mixes, but for a desert animal you’d want to mix sand and soil and skip the soil conditioner as it will hold too much humidity or become dusty when exposed to dry climate conditions.

Mixing potting soil, compost or topsoil with a fibrous, plant-based material such as peat moss or coir will create an aerated medium to properly plant the tank. Peat moss is decomposed sphagnum moss harvested from natural bogs, many of which are home to threatened wildlife. Coco fiber, or coir, is the hairy part of coconut husks and is absorbent and expansive and is environmentally friendly. We do use both, but since peat fiber takes a very long time to break down, soil can be re-used after thorough rinsing and sunbaking to kill microorganisms. You can “solarize” soil by putting it in a black garbage bag and sitting it out in the sun for a summer, this should kill most bugs. If you’ve had a case of cryptosporidiosis or entamoeba, throw it out in sealed plastic bag. Don’t risk the lives of future pets.

Note that any particulate (tiny pieces) substrate can cause issues. Some people have had issues with peat or coir as they can both be ingested and swell in the intestine, causing impaction. Mixing it with the compost or soil reduces the risk. Here are some other tips to avoid impaction:

  • Use a screen to sift our large particles
  • Provide leaf litter cover and/or terrarium moss on top of the substrate.
  • Don’t use with hatchling crested geckos
  • Don’t feed live foods in the enclosure, or use a feeding dish

Step 1

Add 2-3 bags of compost or appropriate soil, and 5 kilo bale of Cocotek coco fiber (coir) in a large tub.

Step 2

Add water to the cocofiber and it will expand like nobody’s business!

Step 3

You can see how the coir becomes loose and mixable. You can screen out the larger bits and strands to make the particles as small as possible to reduce risk of impaction.

Step 4

Be sure to have a qualified dirt inspector on staff after you mix your substrate!

The coco fiber can now be mixed with sifted organic potting soil or compost so that it can support plant growth, as well as harbor a “cleaning crew” of springtails and isopods to breakd down solid wastes and micro-fauna to make the soil mix “bio-active”. This will greatly minimize cleaning and maintenance on the tank.

You can use straight coco-fiber but this can pose impaction risks as the fibers expand when wet, such as in the stomach or intestines if eaten. Mixing with small soil particles helps minimize (but not eliminate) the risk.

13 thoughts on “Crested Gecko Substrates

  1. Pingback: Top 5 WORST Reptile Substrates |

  2. HI I have just got a crested gecko and the guy that gave me him uses sawdust in his tanks thisSafe or should I be buying a different type of bedding iv also bought him a heat mat and new bulb aswell as fruit like mango pineapple and melon he has the repast food but I don’t think he is eating so I got him gecko food that appears to have wee tiny bugs in amongst the powder it sais give it dry I have aswell as the wet repashy he doesn’t appear to be eating though and iv had him for 6days now iv tried hand feeding him but he only licks a tiny small amount before turning his head and walking away, getting a bit worried about the wee guy, any information on what I can do would be a great help thanks.

    • Hi Lesleyann! Sawdust is definitely not safe! Large chunks of bark (Repti-bark) can be used safely but don’t hold moisture as well as other substrates. Don’t feed fresh fruit until he’s eating the Repashy. I don’t recommend feeding any powdered food dry, as captive animals are already prone to dehydration. Try offering gutloaded, dusted insects like crickets (you can feed them the fruit!) to the gecko to stimulate his appetite, then try to get him to eat the Repashy. You can use Pangea or a rotation of other diets (see our CGD page) if they are available. Make sure he has a water bowl in his tank, especially if he’s been housed on sawdust and eating a dry food. Good luck!

  3. Hello! I got a crested gecko a few months ago and initially I used the coconut bark that came with my “starter kit”. However, I noticed that she would consume a lot of it while hunting crickets so I quickly switched it out for a reptile carpet. I’ve noticed that no matter how often I clean it, the cage always had a strong smell to it. The smell doesn’t make my room smell strange, but whenever I open the cage door I can smell it. I was wondering if it could possibly cause harm to her? (I know that build up in the air can kill crickets so I was wondering if it could cause harm to geckos). Regardless, I was wondering if I could remove the bedding all together and just leave her with a glass bottom tank? It would be much easier to clean and she wouldn’t get stuck on it like she does with the carpet when hunting. I can’t find any information on the pros or cons of using not carpet/substrate. Thoughts?

    • I don’t recommend reptile carpet as mentioned in this article because it doesn’t seem to dry out and harbors bacteria, and thus cause some nasty smells. A glass bottom is an option but gets rather difficult to clean every week. If you don’t like using paper towels, you can use butcher paper to help clean up the mess. Good luck!

  4. Do you have any suggestions for getting rid of the little “fleas” that are inhabiting my Crested’s tank. These little bugs are very small, and seem to live under “Munchkin’s” water dish and feed off of her left over Repashy. I remove the food dish everyday for cleaning, but still find new bugs. When I lift up her water dish and check the underside, there are more bugs. Some must be newly hatched because they are barely visible. I don’t think that they are harming my Gecko, but can’t seem to be rid of them. Could it be possible that they were already in the peat moss when I put it in the tank?

    • Hi Debbie! You probably have springtails or soil mites, both are harmless and help break down wastes in the enclosure. They probably did come in on the peat moss. They won’t grow any bigger than what you are seeing. I personally welcome those types of critters for bio-active terrariums, they help cycle the tank.

  5. So I really want a crested gecko and might be able to get one. Would it be okay if I just used coconut fiber as a bedding? And I know this is off topic but my house is generally 66° F to 72° F (during summer). Would this be too cold because I can invest in a heater to put on the side of my vivarium?

    • If the gecko is old enough and over 16-20 grams you could house on coco fiber. We don’t recommend it for young geckos in case they eat it. Paper towel works great for juveniles. You could get a small heat lamp or heat pad and heat one side of the tank up to 80 degrees, but make sure that there is a cool side, around 70-73, to retreat to. Don’t let the whole tank heat up over 78. You don’t have to heat at night with those house temps in the summer. Good luck!

  6. I currently have a moss carpet style thing in my new tank which came with the tank. I want to go with a soil type substrate instead and just wanted to hear peoples experiences with the ABG mix that is recommded here? I am only new to this so I don’t want to make my own soil substrate yet.


    • Hi Kim! It really depends on your intentions. If you just want a natural looking substrate but don’t plan on adding live plants, you could get away with plain cocofiber (sold in brick forms). However, some geckos can end up swallowing it, and it may be hard to pass. That’s why we like to mix it with lighter soil, like compost or potting soil. You can use all organic potting soil, be sure there are no white chunks of perlite that could also be problematic if swallowed. We often use 100% compost with layers of moss and leaves. Putting a layer of leaves over whatever particulate substrate you use can minimize direct contact, so geckos are less likely to ingest it. You don’t have to have a fancy mix, but ABG and other commercial blends do look and smell nice, and are great for plants as well as reptiles & amphibians. Good luck!

  7. Hello,

    I’m thinking on getting a crestie next week. Temperature here is usually around 24°c during day, and can drop to 8°c at night. (I’m from South America) would it be enough adding a heating map to a side of the terrarium?

    • You definitely don’t want them going as cold as 8 degrees C, so some form of heating is necessary. If your room temperature is at least 17C, you probably don’t need extra heating but they prefer 18-26 as a range. Too hot is worse than too cold. Make sure there is plenty of room in the enclosure so they can escape the heat. The cool side should be around 18 and the warm side shouldn’t get over 27.

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