Preparing a Piece of Driftwood Before Adding It to Your Aquarium
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
A piece of driftwood bought at a pet shop or collected in the wild naturally releases tannins that tint the water amber and slightly lower its pH, an effect prized in biotope tanks but one that often surprises beginners. A review by Meinelt and colleagues, published in 2004 in the journal Aquaculture, detailed the use of humic substances and tannins in aquaculture, including their antibacterial properties and their buffering effect on water chemistry. The basics of aquascaping are covered in our bedding and habitat section.
Contents · 5 sections
Why soak the wood before use?
Extended soaking, from a few days to several weeks depending on the wood's density, saturates its fibres and limits a sudden release of tannins once the piece is installed in the final tank. It also lets you check whether the wood sinks without a weight, since a piece that's still too dry tends to float for several weeks.
Should you boil the wood?
Boiling, for one to three hours depending on size, speeds up saturation and removes much of the surface micro-organism load, a step particularly useful for wood collected outdoors rather than bought already treated at a pet shop. A simple cold soak is enough for most wood sold specifically for aquarium use.
Are tannins dangerous for fish?
No, blackwater-tinted water is harmless for the vast majority of species and even replicates the natural conditions of many fish from the Amazon or Southeast Asia. If the colour is an aesthetic concern, activated carbon in the filter media reduces it without cancelling the wood's other benefits; see our guide to filter media for how to position it.
Which wood should you choose, and which should you avoid?
Favour wood sold specifically for aquarium use (mopani, bogwood, Malaysian driftwood), already tested for safety. Softwoods, rich in resin toxic to fish, and driftwood collected on a seashore, loaded with salt, should always be avoided; if in doubt about a decoration's safety, our article on safe driftwood and rocks for the aquarium covers the criteria to check.
- Soak for a few days to several weeks before final installation.
- Boiling recommended for wood collected outdoors.
- Tannins are harmless, reducible with activated carbon for aesthetic reasons.
- Never softwood or salt-laden seashore driftwood.
Frequently asked questions
How long does a piece of driftwood float before sinking?
From a few days to several weeks depending on the wood's density and how long it was pre-soaked; a temporary weight can speed up submersion.
Should tannin-stained amber water be a concern?
No, it's a natural, harmless effect, purely cosmetic, that fades gradually with water changes.
Can the soaking water be reused in the garden?
Yes, this tannin-rich water works fine for watering plants that tolerate a slightly acidic pH.
In our shop, for this use: Hollow moss-effect resin log for aquariums (€20.90) · the whole shop
This guide is part of Planète Pets’s Fishkeeping universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.