Pumice Soil (Floating Pebble)

Pumice soil is a natural, lightweight soil material that has been used as a growing media in horticulture for decades.

It is derived from volcanic eruptions, primarily from quartz and obsidian.

This type of soil is composed of tiny pores and cavities.

This makes it ideal to use in vivariums or terrariums.

Pumice provides excellent aeration, drainage, and lots of support for your plants and reptiles.

In this article, you will learn more about the soil additive and how you can use it in your own tank setup. 

Quick Stats:
Scientific Name Pumice
Botanical Name Pumice Soil
Common Names Soil Pellets, Soil Beds, Pebbles
Origin Volcanic Areas (Mountainous terrain)
Size 0.1mm to 2mm
Color Gray
PH Impact Neutral
Elemental Type Extrusive Igneous Rock (Mafic)

What Is Pumice Soil?

Pumice soil is a by-product of pumice rocks naturally grounded into gravel.

It is made up of volcanic rock and comes in two forms.

One is a sand-like composition while the other is a pebble-like aggregate.

Both can be used interchangeably in vivariums, depending on your desired setup.

Generally, soil pellets are ideal for planted tanks for providing better aeration and root support.

On the other hand, if you want to create a rocky landscape with lots of terraces and bumps, pebbles might be the better choice.  

Pumice Soil For Terrariums Info Card

Pumice Soil Facts

Volcanic ash created from volcanic eruptions over millions of years has merged and solidified from molten rock to create pumice.

Known as a porous rock, pumice is created by trapped gas bubbles expanding during the cooling process of magma.

The pores present in the material help regulate the aeration process, providing enough oxygen for roots to thrive without the risk of over-saturation.  


Pumice soil is a light-gray material that comes in the form of sand-like granules and pebble-like chunks.

It can be found in sizes ranging from 0.1mm to 2mm, making it an ideal substrate for terrariums, vivariums, or any other type of containment requiring soil properly.

Pumice is lightweight and has little to no dust.

This aids in keeping the substrate aerated, which provides lots of oxygen to plant and reptile roots. 


Pumice soil is mostly found in volcanic areas in mountainous terrain.

Cooling magma is surrounded by air and this combination solidifies into pumice.

The porous nature of this material makes for an ideal seismic-resistant soil material, making pumice one of the topmost choices for cultivating lush terrain in terrarium and vivarium setups. 

Environmental Influence

Pumice soil is a naturally neutral substance with a pH of 6-7.

This means it is not overly acidic, so it can be used safely in more sensitive tanks.

The substrate also is able to retain a small number of nutrients and moisture, making it great for terrariums or vivariums that lack a lot of natural life.

Additionally, pumice is one of the few materials that can help raise PH levels if it’s too low. 

Vivarium Type

Pumice soil can be used for many different types of vivariums.

It can be used as a stand-alone substrate for reptile enclosures, or as a soil amendment for more heavily planted tanks.

The soil additive is also useful in biotopes, as it is buoyant enough to provide soft bedding for snakes, lizards, and other aquatic species.

Furthermore, pumice can be used to create a rocky landscape with plenty of uneven areas, adding both aesthetic value and beneficial rooting components. 

Here is a recommended list of vivarium types compost is commonly used in:

  • Paludariums – Half aquatic/ half terrain-based enclosure.
  • Terrariums – Fully terrain-based enclosures with little to no aquatic features.

Vivarium Usage

When using pumice in vivariums, you should keep in mind that it is a lightweight type of soil.

This means it should not be used as the sole substrate in any enclosure.

It’s best used as a soil amendment, mixed with heavier types of substrate, such as potting mix or other substrate materials.

Mixing 1 part of pumice soil with 3 parts of heavy substrate will provide the necessary support and aeration most plants and reptiles need to survive.


Pumice soil has many advantages for vivarium use.

It doesn’t need to be replaced very often as it does not break down as quickly as other soil mixtures.

It also provides an excellent balance of light and heavy particles, so it can be used with aquatic and terrestrial species.

Its porous nature ensures that roots will have access to plenty of oxygen, and it is light enough for soil inhabitants to burrow easily.

Finally, pumice does not need to be mixed with additional fertilizer since it contains a few nutrients already.


Unfortunately, one of the main drawbacks of pumice soil is that it is quite dry and can sometimes be difficult to dampen.

Due to its lightweight nature, it is also prone to be carried away in the water.

If you keep aquatic species in your tank, you should use a heavy substrate in the bottom to keep the pumice from being washed away.

Additionally, while this type of soil additive is an excellent choice for planted tanks, it should be used in small amounts as it does not contain the same levels of nutrients as other soil mixtures do.  

Buy Pumice Soil

Pumice soil can be purchased from many different sources.

It is best to buy from a reputable seller who provides information on where the material has been harvested from and how it has been processed.

When shopping for pumice in its smaller soil form, you should look for sizes that best suit your needs.

Smaller sizes work better for planted tanks, while larger sizes are better for reptile enclosures. 

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Pumice Soil Preparation & Tips

Before you use pumice soil in your tank…

It is best to rinse it off first to remove any dirt or debris.

This can be easily done by submerging the soil in warm water. Follow that by vigorously rubbing it to remove any dust or dirt.

Once rinsed, pumice can be mixed with other soil amendments as desired.

It is also beneficial to bake the soil in the oven at a low temperature.

This will kill off any harmful microbes or parasite eggs. 

Pumice Soil Substitutes

If you feel that pumice soil is not the right choice for your tank. Other soil alternatives include peat moss, coconut coir, and loam.

Peat moss is great for hydroponics, as it is highly absorbent and retains lots of moisture.

Coconut coir is also an excellent option for planted tanks as it is packed full of nutrients and provides ample aeration.

Finally, loam is a great mixture of sand, silt, and clay, providing plenty of aeration and water retention for a balanced substrate. 

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Much like pumice rocks, the soil alternative is an excellent choice for any vivarium or terrarium setup.

It provides the necessary aeration and drainage for your tank inhabitants, and its porous nature allows for ample amounts of oxygen and moisture.

Pumice soil is lightweight and does not need to be replaced very often.

It is also great for planted tanks and reptiles, as it contains a few nutrients and is not overly acidic.

When used in combination with other soil amendments, it can create a lush, thriving environment.

Frequently Asked Questions

Pumice soil is a type of lightweight, volcanic soil. It is made of an igneous rock that is porous and full of tiny air bubbles.

Pumice is high in fertility and water retention, making it ideal for growing different types of plants. Additionally, the structure of pumice soil allows for adequate drainage, aeration, and oxygenation.

Pumice is a very light, porous stone with a high nutrient content that can be beneficial for the soil. It is good for improving the structure of the soil, improving drainage, and aeration, as well as providing more nutrients and minerals for the plants.

Pumice also helps increase the water retention of soil, thus providing a beneficial ecological environment for plant growth.

Making pumice soil is easy! First, mix the pumice with water until it is wet but still has some dry pieces. Then, mix in compost or another organic material for nutrients, and Perlite for aeration. Finally, mix in some more water until desired consistency is reached. Your pumice soil is now ready to use for your plants!

Yes, pumice can raise soil pH. Pumice is made of tiny pores filled with air and gas. This structure raises soil PH, making the soil less acidic. Pumice also helps retain water, increase drainage, and improve soil aeration. It can be used as a soil amendment to improve soil fertility and enhance crop production.

Yes, you can grow plants in pumice! Pumice is a type of porous rock full of air pockets, making it an ideal soil additive for aeration and drainage. It helps to retain moisture, and it releases minerals important for plant growth such as potassium and magnesium. Pumice also helps to balance soil pH and it can even help keep snails and slugs away from your plants.

Yes, you can mix perlite and pumice. Both are very lightweight and commonly used in gardening and horticulture. Perlite is made from volcanic glass, while pumice is made from a type of volcanic rock. Mixing the two materials together can help improve drainage and aeration for potted plants, allowing for welldrained soil that is perfect for growing your plants.

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