The short answer
Driftwood floats because it’s still full of air. The permanent fix is to soak it until it’s waterlogged, which can take days to weeks. Until then, weigh it down or attach it to a piece of slate buried in the substrate so it stays exactly where you want it. Once the wood has fully saturated, it will sink on its own and the anchor becomes optional.
Why it floats in the first place
Fresh wood is buoyant because air is trapped in its structure. As water slowly replaces that air, the wood gets denser and eventually sinks — but that soaking process takes time, and dense hardwoods are the most stubborn. Fighting the float is really just a matter of holding the wood down long enough for physics to do its work.
Ways to hold it down
- Attach it to slate: screw or glue the wood to a flat piece of slate, then bury the slate under the substrate. This is the tidiest, most reliable anchor.
- Wedge it under rock: trap the base under a heavy piece of hardscape.
- Glue it to a rock: aquarium-safe super glue gel bonds wood to a stone base instantly.
- Weigh it during soaking: in a bucket, pile on something heavy so it stays submerged and saturates faster.
Getting the scape right
Slate anchors let you position wood confidently while planning your layout, and they disappear under the substrate. For arranging wood, rock and plants together, see aquascaping for beginners, and check whether your rocks are safe before adding them. Browse the substrate hub for the base that hides the anchor.