Driftwood can work in an aquarium, but only if it's prepared correctly and matches your tank setup

Raw driftwood pulled from a beach or river will leach tannins into your water, turning it brown and lowering the pH—which harms most fish. Boiled or commercially treated driftwood is safe and won't cloud your tank. The wood itself won't rot or break down quickly enough to foul the water, and many fish species use it for hiding, grazing, and resting. The real question isn't whether driftwood belongs in an aquarium, but whether the specific piece you have is prepared, sized right for your tank, and suitable for the fish you keep.

Driftwood also floats for weeks after boiling, so you'll need to anchor it to keep it from drifting into your filter or trapping fish. Once weighted down and settled, it becomes a stable part of your tank that lasts several years with minimal maintenance.

Key Takeaways

  • Untreated driftwood releases tannins that discolor water and lower pH, so boil it for 15 to 30 minutes or buy pre-treated pieces from aquarium stores.
  • Driftwood must be weighted down or anchored because it floats for weeks or months even after boiling, and floating wood can trap fish or damage equipment.
  • Soft-bodied fish and invertebrates like plecos, shrimp, and snails benefit from driftwood for grazing and shelter, while aggressive fish may use it to claim territory.
  • Driftwood from unknown sources may carry parasites, bacteria, or pesticide residue, so only use pieces from aquarium suppliers or thoroughly cleaned natural sources.
  • Boiled driftwood lasts three to five years in a tank without rotting, but it will gradually soften and shed fibers that can cloud water if not removed.

Why untreated driftwood causes problems in your tank

Driftwood contains tannins—natural compounds that stain water brown and lower pH. In a new tank, this happens fast: within hours, the water around the wood turns tea-colored. Over days, the entire tank becomes noticeably darker. For fish that need neutral or slightly alkaline water (like goldfish, cichlids, or most community fish), this pH drop can stress or sicken them.

The tannin release slows after a few weeks, but untreated wood will continue leaching for months. Some aquarists want tannins for blackwater tanks that mimic acidic river environments—those tanks are set up specifically for fish like tetras and discus that thrive in low pH. If that's not your goal, boiling removes most tannins before they enter your tank. Even boiled wood releases some tannins over time, but the amount is small enough that regular water changes keep your pH stable.

How to prepare driftwood before putting it in your aquarium

Boiling is the standard method. Place the driftwood in a large pot, cover it with water, and bring it to a rolling boil. Boil for 15 to 30 minutes depending on the wood's size and density. Larger pieces may need 45 minutes. The wood will release brown water—this is tannin leaving the wood, which is exactly what you want. You may need to change the water and boil again if the water is still very dark after the first round.

After boiling, remove the wood with tongs and let it cool on a clean surface. Do not use the boiling water in your tank; discard it. Once cool, rinse the wood under tap water and inspect it for soft spots, mold, or debris. If you see fuzzy growth, scrub it gently with a soft brush. Boiled wood is safe to add to your tank when ready, though it will still float for several weeks until it becomes waterlogged and sinks.

An alternative is to buy driftwood from an aquarium supplier. These pieces are already treated and ready to use. They cost more than natural driftwood but save you the boiling step and the uncertainty of what you're bringing into your tank. Aquarium-store driftwood is inspected for parasites and treated to remove tannins, so you can add it directly to your tank without preparation.

Keeping driftwood submerged so it doesn't float away

Even after boiling, driftwood floats. It can take two to four weeks to become heavy enough to stay on the bottom. During that time, it will drift around your tank, potentially damaging your filter intake, trapping small fish, or pushing against the glass. You need to anchor it from the start.

The easiest method is to tie the wood to a rock or piece of slate using fishing line or plant weights. Wrap the line around both the wood and the anchor, then place them together on the substrate. The line is nearly invisible and won't harm fish. Another option is to wedge the wood between two rocks or against the back wall of the tank so it can't float up. Some aquarists use suction cups designed for aquarium plants, though these work best on smaller pieces. Once the wood becomes waterlogged after a few weeks, you can remove the anchor if you want, though leaving it in place keeps the wood from shifting.

Do not use glue, nails, or screws. Aquarium-safe silicone can work if you're attaching wood to a rock, but it's permanent and makes the wood harder to remove later if you need to clean it or replace it.

Which fish and animals benefit from driftwood

Plecos and other bottom-feeding fish rasp on driftwood to wear down their constantly growing teeth. Shrimp and snails graze on the biofilm and algae that grow on the wood's surface. Tetras, rasboras, and other small fish use it as shelter and resting spots. Cichlids and other territorial fish use driftwood to divide their space and reduce aggression by creating separate zones.

Soft-bodied fish like corydoras catfish and kuhli loaches appreciate the smooth surfaces and hiding spots. Even fish that don't interact directly with the wood benefit from the visual complexity it adds—a tank with driftwood and plants looks more natural and reduces stress from boredom. Fish that don't need driftwood include goldfish (which uproot and damage decorations), bettas in small tanks (where driftwood takes up too much space), and aggressive species that may use it as a weapon or hiding spot to ambush tank mates.

Signs that driftwood is breaking down and needs replacement

Boiled driftwood lasts three to five years, but it does eventually soften. Watch for these signs: the wood becomes mushy or crumbly when you touch it, fibers shed into the water and cloud it, or the wood develops a strong foul smell. If you notice any of these, remove the wood and replace it.

Mold or fuzzy white growth on the surface is normal and harmless—it's biofilm that fish graze on. You can leave it or gently scrub it off. Black spots or slime are also normal and don't require action. Only remove the wood if it's actively falling apart, if pieces are breaking off into the water, or if the smell suggests rot rather than the mild earthy smell of healthy wood.

Where to source driftwood safely

Aquarium stores sell pre-treated driftwood in various sizes, usually labeled by length. This is the safest option because you know it's been inspected and prepared. Prices vary by size and type, but expect to pay more than you would for natural wood you collect yourself.

If you collect driftwood yourself, take it only from clean sources: a sandy beach far from industrial areas, or a river with clear water and no visible pollution. Avoid wood from areas that may have been treated with pesticides or herbicides. Once you have it, boil it thoroughly before use. Do not use driftwood from pet stores' general decoration sections unless they specifically label it as aquarium-safe. Wood sold for terrariums, vivariums, or general crafts may have been treated with finishes or chemicals that are toxic to fish.

Frequently Asked Questions

Can I use driftwood from the beach or a river without boiling it?

You can, but you'll deal with tannin staining and possible parasites or bacteria from the source water. Boiling takes 30 minutes and removes most tannins and pathogens. It's worth the effort if you want clear water and healthy fish.

How long does driftwood last in an aquarium?

Properly boiled driftwood lasts three to five years before it becomes too soft and breaks apart. Some pieces last longer depending on wood type and how much your fish interact with it. Replace it when it starts shedding fibers or smells bad.

Will driftwood make my aquarium water acidic?

Untreated driftwood lowers pH by releasing tannins. Boiled driftwood releases far fewer tannins, so the pH drop is minimal. If you're concerned, test your water before and after adding the wood. You can also do partial water changes to dilute any remaining tannins.

Can I use driftwood in a tank with live plants?

Yes. Driftwood doesn't compete with plants for nutrients and actually provides a surface for moss and smaller plants to attach to. Tie moss or anubias to the wood with fishing line, and they'll grow across it over time.

What if my driftwood has a strong smell?

A mild earthy smell is normal. A strong, foul smell suggests rot or mold inside the wood. Boil it again and let it dry completely. If the smell persists, replace the wood—it's breaking down and may foul your water.