Many aquarists, when designing their aquarium decor, opt for wood to give a more pleasing aesthetic.  Others try to stay away from wood because it can, over time, appear dingy and unattractive.

When making the decision of wood or no wood, follow your gut and create an environment you will enjoy watching and your aquarium occupants will enjoy exploring.

Adding wood will give a natural feel to the aquarium, and give fish an obstacle course they can enjoy swimming in and through.

Wood can be an interesting addition to the aquarium environment providing a few precautions are taken.

Several species of wood are known to be toxic to fish and should be avoided in aquariums. Here are a few examples:

Cedar: Cedar wood contains natural oils and resins that can be toxic to fish. These substances can leach into the water and harm the fish.

Pine: Pine wood is also known to contain resins and oils that can be toxic to fish. It can cause water contamination and negatively affect the health of aquarium inhabitants.

Oak: Oak wood can release tannins into the water, which can lower the pH and affect water chemistry. While tannins themselves are not necessarily toxic, excessive amounts can be detrimental to some sensitive fish species.

It’s essential to research and choose wood that is specifically considered safe for aquarium use. Driftwood, Malaysian driftwood, and mopani wood are popular choices because they have been widely used in aquariums without causing harm to fish or plants.

Always ensure that the wood has been properly prepared and any potential toxins have been removed before adding it to the aquarium.

Before adding any wood to the aquarium, it’s crucial to properly prepare it.

Do your research to see if the wood you are adding to the aquarium is non-toxic to aquatic life.

Inspect the wood for surface contaminants.  This is a difficult step due to the inference process necessary to judge wood contaminants.

The wood will not tell you what it has been exposed to.  When out in the woods, it’s difficult to carry a mass spectrometer with you to analyse wood samples for contaminants.

As the aquarist, you need to infer what the wood might have been exposed to based on where the wood was found.  Wood near an industrial plant is probably not a good candidate for the aquarium.  However, wood found on a tree in a sparsely populated area is probably safer from surface contaminants.

When you have an interesting piece of wood selected remove the bark and cambium layers so that only wood is showing.  Then soak it in water for several weeks, or boil it to remove any tannins and other organic compounds that can color the water and affect pH levels.

When fitting wood to the aquarium decor be certain to already have a gravel base in the aquarium floor.  Sit the wood into the gravel and then lay it in such a way so as to not block water flow and allow an aquarium vacuum access to the floor of the aquarium.

Keep in mind that wood will rot in the presence of O2 (oxygen), bacteria, and fungi, which will be produced by plants and biological waste products in the aquarium.  Secure the wood, but not too secure that it can’t be removed at a later date without disturbing rocks or other aquarium decor.

After introducing wood the water chemistry must be closely watched.  Even though the wood was soaked and/or boiled it may still leach tannins.  Tannins may cause the water to turn yellow or brown.

Some fish species, like those from blackwater habitats, can tolerate tannins, others may be sensitive to changes in water chemistry. Regular water testing and monitoring can help ensure that the wood is not negatively impacting the water parameters and the health of the aquarium occupants.

If tannins are detected prepare to perform a water exchange.  The frequency of water exchanges will be dependent upon the amount of tannins present in the water.  Increased discoloration (short period of time) will translate into more frequent water exchanges.

Besides providing an aesthetic appeal, real wood in an aquarium can offer additional benefits. It can create hiding places and shelter for fish, particularly for those that prefer a more natural habitat.

Wood can also encourage the growth of beneficial biofilm and provide a surface for beneficial bacteria to colonize, contributing to the biological filtration of the tank.

If wood with a light or white color to the wood fiber is selected, it will reflect light into areas not readily lit from the aquarium lights.  This effect will add depth and interest to the aquarium.

If the style of the aquarium is going to be a bit industrial with angular pieces of wood, try not to select pressure treated wood as the aquarium wood.

Pressure treated lumber has a significant fungicide that has been forced deep into the xylem and phloam of the wood.  As such, it will be almost impossible to remove or leach out the chemical compounds from the wood.