When trying to find that perfect piece of driftwood for your aquarium you have to remember that not all wood is created equal. Or at least not all wood is appropriate for aquarium use. The easiest way to stay safe is to only purchase driftwood marketed specifically for aquatic environments. If, however, you want to be adventurous and try using wood that you find yourself, you’ll want to familiarize yourself with what wood is safe first.
Aquarium safe wood
Below is a list of wood that is generally thought to be safe for use in aquariums. This is not an exhaustive list so be sure to research any wood you find, that is not listed, before exposing your fish to it.
Alder
Alder wood is classified as Alnus spp. It comes from deciduous trees commonly found near rivers, streams, and wetlands. This type of wood can be found all over North and Central America, Europe, and Asia.
Apple
Applewood is classified as Malus spp. It is made up of many different species of apple bearing trees. This common wood can be found throughout the temperate zone of the Northern Hemisphere.
Ash
Ashwood is classified as Fraxinus spp. This particular species, featured below, of flowering Fraxinus is commonly known as Texas ash. As the name implies, it can be found in eastern Texas.
Azalea
Azalea, in particular the roots and otherwise known as spider wood, are classified under Rhododendron spp. Not to be confused with other forms of Rhododendron, which are toxic. Azaleas are native to North America, Europe, and Asia.
Basswood
Basswood is classified as Tilia spp. Basswood is the common name for species native to North America. Other common species under Tilia, and native to Europe, are often referred to as Linden. You may hear these referred to as lime trees but they should not be confused with the actual fruit-bearing plants having the same name.
Beech
Beechwood is comprised of several species of Fagus. All are deciduous hardwoods and depending on species are native to the temperate zones of North America, Europe, and Asia.
Cherry
Cherry wood comes from a variety of fruit-bearing trees classified as Prunus spp. This is the same genus that apricot, plum, and almond trees are also found. These various species can be found within the northern temperate regions.
Cholla
Cholla comes from the branches of some cacti that fall under the genus Cylindropuntia. The tubular structure of this plant is what gives it its unique look. These cacti grow throughout the southwest region of the United States as well as northern Mexico. They are also slowly finding their way into South America.
Elm
Elm trees are classified as Ulmus spp. The trees that give us this wood are made up of both deciduous and semi-evergreen trees. Elms grow just about everywhere in the northern hemisphere. Most notably is that Elm trees are a popular choice for crafting bonsai.
Hawthorne
Hawthorne is classified as Crataegus spp. This genus is made up of hundreds of different species. This is a very strong wood that can be found in the temperate regions of the northern hemisphere. Hawthorne is another common choice for a bonsai that flowers.
Madrone
Madrone, also known as madrone, is another one of those evergreens that is okay to use in an aquarium. Its scientific name is Arbutus menziesii and it grows in the North American western coastal region. This wood will have a brown pinkish color with dark red patches. I’ve never seen this for sale as aquarium driftwood but it would be a really pretty option if you could find it.
Malaysian
Malaysian driftwood is one of the most common aquarium driftwoods available. They can come from a wide range of wood types in the Diospyros genus ranging from a medium brown to almost black in some cases. The most common species used is Diospyros ebonasea, otherwise known as Malaysian blackwood.
Manzanita
Manzanita driftwood has a beautiful mix of oranges, browns, and reds and is very durable in an aquatic setting. About 60 different species belonging to the Arctostaphylos genus have the common name of manzanita. They can be found throughout the western regions of North America.
Mesquite
Mesquite is made up of 13 different species belonging to the genus Prosopis and are all leguminous. Mesquite ranges in color tones and grows natively in the southwestern subtropics of North America. Creeping mesquite is the only exception which grows in the subtropics of South America.
Mopani
Mopani driftwood, also known as mopane, has the scientific name Colophospermum mopane. Its colors range from medium to dark brown. This very dense hardwood grows in the middle south region of Africa. Mopani can be expected to release a lot of tannins and humic acid into your water column.
Oak
Oaks are comprised of about 600 different Quercus species of the Fagaceae family. Oak trees grow throughout the temperate zone of the northern hemisphere. This hardwood is generally light brown. I’ve personally never seen oak being used in an aquarium but I supposed if it was treated right it could be. This does not include live Oak.
Pear
Yes, pear, the same tree that bears the fruit. There are about 30 species of pear under the genus Pyrus and while some are used as a source of food, others are used solely for wood production. Pearwood ranges from a pale pink color to a reddish-brown and can be found in Europe, Asia, and North Africa.
Rosewood
About a dozen species under the Dalbergia genus can be considered rosewoods. The two most common types are Brazilian and East Indian rosewoods and are grown in those respective regions. Often identified as being dark chocolate or purple-brown in the Indian species, and reddish dark brown for Brazilian species.
Wood to avoid in aquariums
Below is a list of wood that is generally thought to be unsafe for use in aquariums. This is not an exhaustive list so be sure to research any wood you find, that is not listed, before exposing your fish to it.
Cedar
Cedarwood is a name given to many different types of plants and trees found all over the world. These span 9 different families, 29 different genera, and 32 different species. It’s a fairly broad term, as you can see. Although not all are coniferous, most are, and all should be avoided.
Cypress
Cypress wood comes from several different trees or shrubs that are all coniferous. They are made up of about 35 species belonging to various genera. These softwood species can be found all over the world and can be dangerous to use in your aquarium.
Douglas Fir
Douglas Fir is a coniferous softwood that is grown in western North America. It’s a single species, Pseudotsuga menziesii with several subspecies. Although belonging to the same family, Pinaceae, Douglas Fir is not a true Fir.
Fir
Firs, or Abies spp., is the common name for over 50 species. All coniferous and all softwood that would not be ideal for aquarium use. Fir grows in North America, Central America, Asia, Europe, and Africa. Not to be confused with Douglas Fir.
Grapevine
Grapevine, or Vitis spp., is grown throughout the world for, you guessed it, growing grapes. I’ve seen mixed reviews on this one. Although it’s listed in most places as an unsafe wood for aquariums, I’ve seen many people report using it with success. Maybe the issue is the pesticides used for commercial grape growing. Either way, it’s usually found with its bark still on and should be removed.
Hemlock
Hemlock is comprised of 4 genera and 30 species of trees or plants. The biggest threat here is that most of the species of Hemlock are extremely poisonous. One genus, Tsuga, has 11 of those species and are not poisonous. However, they are rich in sap and still not good for your aquariums. Found in all over the world.
Horse chestnut
Horse chestnuts or Buckeyes fall under the genus Aesculus and make up about 15 species. These should be avoided because their poison is toxic. There is a history of these plants being used specifically to kill fish too. These can be found throughout the temperate zone of the northern hemisphere.
Juniper
Junipers are a softwood coniferous tree belonging to the Juniperus genus with up to 67 species. These are grown throughout the northern hemisphere. Junipers contain a lot of sap that could pollute an aquarium.
Kauri
Kauri trees are made up of 22 species from the Agathis genus. Grown all over the Pacific islands and parts of Australia. This coniferous tree is full of resins that have many practical uses. None of which are good for aquatic life.
Larch
Larch is a type of tree that make up 11 different species under the Larix genus. They are a group of conifers that grow throughout North America, Europe, and Asia. Larch is a prime example of a coniferous tree that is not an evergreen.
Lilac
Lilac, or Syringa spp., are large flowering shrubs or small trees from the Oleaceae family. This popular and aromatic plant can be found growing in North America, Asia, and Europe. Thought to be toxic, there are reports of this not being true. I’ll leave this here as unsafe until proven otherwise.
Live Oak
Live Oak is a common name in North America for Oak trees that are evergreen. They fall under the same genus as Oaks, Quercus, and are the only Oaks that should be avoided in aquariums. Live Oak is different than regular Oak trees due to them being abundant in sap.
Pine
Pine trees are a coniferous evergreen with softwood. Pines belong to the genus Pinus and according to theplantlist.org, there are 175 accepted species of pines belonging to this genus. Pine grows throughout the temperate zone of North America.
Rhododendron
Rhododendron is a genus of small to medium-sized bushes or trees containing 1,024 species. Commonly found in Asia and North America, some Rhododendrons contain a toxin called grayanotoxin that can be deadly to animals. I’m uncertain if it is present in the wood but it is commonly accepted to be unsafe in aquariums.
Rimu
Rimu is a large single-species tree, Dacrydium cupressinum, that is grown on New Zealand’s 3 largest islands. Like most coniferous trees, Rimu is high in its sap content and not safe for aquatic use.
Sequoia
Sequoia trees are also known as California redwoods because that is where they are native to. Their scientific name is Sequoia sempervirens and is the only living species in that genus. Other species of Sequoia existed but are now extinct.
Spruce
Spruce trees make up 35 different species of trees that fall under the Picea genus. They are a coniferous evergreen tree that is found throughout the temperate zone of the Northern Hemisphere, especially within the Taiga biome. Resins from these trees help create turpentine.
Walnut
Walnut trees, Juglans spp., spread across 21 species. These are grown all over the temperate zone of the Northern Hemisphere. Walnut trees, especially black walnut species, contain a toxin called juglones that can be toxic to your fish or other plants growing in your aquarium.
Yew
Yews refer to a genus of trees called Taxus. There is a total of 9 species of Yew but are commonly just lumped together as Taxus baccata. Most every part of a Yew is considered toxic and should be avoided.
The evergreen myth
A common misconception is that all evergreens are unsafe for use in an aquarium. While this is mostly true, it should be used more as a standard instead of a fact. There are examples where this rule fails such as Elms, which some are semi-evergreen. Cholla, which is perfectly safe, is an evergreen as well as Madrone.
The true culprit when you hear to stay away from evergreen trees are actually conifers. Cone bearing, or coniferous, trees are very high in sap and that sap will leech into your water column.
Exceptions to the rules
The purpose of this list of safe and unsafe woods is for quick reference and should always be researched for your exact application. Avoiding conifers or softwoods is a general guideline to keep your aquarium safe. Whether it’s the sap, oils, natural chemical deterrents, or just the fact that it would break down rapidly in an aquatic setting.
With that being said, just about any wood can be used in your aquarium. That is if it was properly treated. Even a tree that is rich in sap will eventually release all that it can and the same is true with any toxin as well. As for avoiding softwoods because they break down too fast, it doesn’t stop us from using Cholla wood, does it? Any “unsafe” wood can eventually become safe. It’s just safer to assume that it’s not.
Using branches found in nature
Now that you are familiar with what types of wood are safe and what’s not safe, you may feel confident to use random branches or roots that you find in nature. After you reference the wood you found with this list, you’ll be ready to take the next step. Don’t just throw found wood into your tank though. You’ll want to make sure that you properly clean and prepare the wood first.
