How to Prepare Driftwood for Your Aquarium

Most driftwood releases harmless tannins

The first thing to know is that most driftwood releases tannins, natural compounds that leach out of the wood and tint the water a tea-colored brown. Tannins are harmless and even beneficial to many fish, gently softening the water and mimicking natural blackwater habitats. Still, many aquarists prefer clearer water, and soaking the wood beforehand releases much of the tannins so they do not discolor your display as heavily.

Give the wood a thorough cleaning first

Before soaking, give the wood a thorough cleaning. Scrub it under running water with a stiff brush to remove loose debris, dust, and any dirt trapped in the crevices. Do not use soap or detergents, which can leave residues harmful to fish. A good scrub removes surface contaminants and any loose bark or fragments that would otherwise break off and float around your tank.

Fresh driftwood usually floats until it waterlogs

The next challenge is that fresh driftwood usually floats, sometimes stubbornly, because it has not yet absorbed enough water to become dense. Soaking the wood for days or weeks lets it slowly waterlog until it sinks on its own. Some people speed this along by boiling smaller pieces, which also helps release tannins and sterilizes the surface, though large pieces are too big to boil and simply need patience.

Anchor wood that won't sink on its own

If you cannot wait for a piece to waterlog, or if it is too large to sink even after soaking, you can anchor it instead. Attaching the wood to a piece of slate or stone with aquarium-safe fasteners, or wedging it under your hardscape, holds it down until it eventually becomes waterlogged enough to stay put. Burying part of it in the substrate works well too and looks natural.

A white biofilm in the first weeks is normal

Do not be alarmed if new driftwood develops a white, slimy biofilm in its first weeks underwater. This fuzzy growth is a normal, harmless fungus that feeds on sugars in the wood, and it disappears on its own as the wood settles in. Many algae-eating fish and shrimp will graze it away happily. Once your wood is clean, soaked, and secured, it will serve as a beautiful and lasting foundation for your aquascape.

Frequently asked questions

Why does new aquarium driftwood turn the water brown? Most driftwood releases tannins, natural compounds that leach out and tint the water tea-colored brown; they're harmless and even beneficial to many fish, but soaking beforehand reduces the discoloration.

Why does new driftwood float in an aquarium? Fresh driftwood hasn't absorbed enough water yet to become dense, so soaking it for days or weeks lets it slowly waterlog until it sinks on its own, or boiling smaller pieces speeds this up.

How do I make driftwood sink faster in an aquarium? Boil smaller pieces to speed waterlogging and release tannins, or anchor larger pieces to slate or stone with aquarium-safe fasteners, or bury part of the wood in the substrate.

Is white fuzz on new aquarium driftwood dangerous? No, it's a normal, harmless fungus that feeds on sugars in the wood and disappears on its own as the wood settles in; many algae-eating fish and shrimp will graze it away.