When a new aquarium root turns the water brown, it is easy to think that something is wrong. In many cases, it is not dangerous at all. The brown colour usually comes from tannins, humic substances and other natural substances in the wood.
This is the same type of substance that gives many natural aquatic environments a tea-coloured or darker tone. In Amazonian and blackwater environments, this colour is part of the environment itself.
Tannins and humic substances are not dirt
Tannins and humic acids are natural organic substances. They can give the water a yellowish-brown, tea-coloured or slightly smoky tone. For some fish, it is a very natural environment, especially species that come from forest streams, flooded riparian zones or humus-rich waters.
This does not mean that everyone wants brown water. Many people want a clear aquarium where plants, fish and scape are clearly visible. Therefore, the question is not only whether tannins are dangerous, but how much root release and how it fits the type of aquarium you want.
Different types of wood colour differently
Some aquarium roots can release a lot of colour in the beginning. Mopani and some types of classic bogwood are known to be able to colour the water clearly. Other roots colour less, but may produce more biofilm or slime in the beginning.
Tuskwood usually behaves more slowly. Because it is old bog wood that has been in an oxygen-poor peat bog environment for a long time, much of the soluble material is already altered, decomposed or leached. Tuskwood can still release humic substances and tannins, but not normally in a way that turns the water a strong brown colour.
In some aquariums, you may see a slight darkening of the water colour after a while, especially if you do few water changes. This is not the same as the water becoming heavily discoloured.
Is brown water bad for fish?
Not automatically. Rather, for many fish, humic substances can be part of a natural and safe environment. This is why roots, leaves and humus-rich water are often used in aquariums for discus, scalars, tetras, apistogramma and other South American species.
However, you should always distinguish between natural colouring and poor water quality. Brown water from tannins is one thing. Turbid, smelly water, rotting wood or heavy deposits are something else.
How to reduce colour if you want clearer water
If you find that the root is colouring too much, you can pre-soak it in a bucket or tub. Change the water regularly and watch the colour fade. In the aquarium, regular water changes will also help.
Activated carbon in the filter can be used temporarily if you want to remove colour faster. It is not necessary to use it all the time, but it can be useful if you want to have clearer water for photography or if the root is more colourful than expected.
For Tuskwood, we mainly recommend rinsing, brushing and soaking. Boiling is normally not the right way to go for genuine bogwood, as hard heat can affect the natural structure and properties of the material.
In short
Aquarium roots colour the water brown as they release tannins and humic substances. This is not automatically negative, and for many fish it is a natural part of the environment.
Tuskwood normally releases such substances slowly and mildly, without giving a strong brown colouration. This makes it a good choice if you want the feel of real bogwood and natural wood, but still an aquarium that feels clear, stable and easy to enjoy.
Read more in the article what is real bogwood?.