If you’ve added driftwood to your aquarium for both the benefit of your fish and for the aesthetics of the tank, you might be surprised if the driftwood floats rather than sinking to the bottom.
Why is this and what can you do about it?
Driftwood that isn’t yet waterlogged may be too light to sink and may float in your aquarium until it has absorbed enough water to hold it down. Some driftwood is simply too light and hollow to sink regardless of what you do to prepare it and may need to weighed down or held in place.
When choosing driftwood for your aquarium, you should choose pieces that are heavy enough to sink and that fit your tank. But there are things you can do to help weigh the wood down if required, which we’ll discuss below.
Why won’t driftwood sink to the bottom of my aquarium?
Some driftwood is simply too light and hollow to sink and will instead float. Some pieces of wood are too buoyant to sink and may never be suitable on its own for an aquarium.
Not preparing the driftwood prior to putting it in your aquarium can also be a problem. If you neglect to properly condition and prepare the driftwood before putting it in the aquarium, it can not only harm your fish but may also prevent the wood from sinking as you like.
Driftwood that has been through numerous cycles of being saturated with water and dried by the sun gets to the point where oxygen inside the wood has been eliminated. The space is now occupied with water, totally saturating the wood, and adding weight to it that will cause it to sink rather than float.
If your chosen driftwood has too much oxygen in the cavity, it may not sink and will instead float. Regardless of whether you purchase driftwood or source it yourself, there are things you can do to ensure it stays at the bottom of the aquarium.
How can I make driftwood remain at the bottom of my aquarium?
While you ideally want driftwood that sinks on its own, you can use several methods to accomplish this if necessary. Here are the steps to ensure your driftwood will remain at the bottom of your aquarium and not float.
1. Clean the driftwood. While cleaning the driftwood won’t help it sink, it’s part of the process. Scrub the wood with a brush and warm water to remove surface dirt and debris.
2. Soak the driftwood. Completely submerge the wood in a bucket of water for up to several weeks. It can take this long for the wood to release its natural tannins and to completely saturate and soak the wood. The longer, the better.
3. Boil the wood. After soaking the driftwood, boil it for several hours to remove remaining contaminants and kill off any disease that the wood contains. A good rule of thumb is to boil it for 1-2 hours and then replace the water and boil it again. When the water runs clear, you can stop boiling it. Continue boiling until the wood sinks and stops floating.
By going through this process, you will clean and sterilize the wood while also properly saturating it to ensure it sinks.
Tip: To hedge your bet, try soaking several pieces of driftwood in a large stock pot rather than just one. This way, you can choose the best piece(s) and discard any wood that doesn’t survive the boiling which indicates that it isn’t suitable for your aquarium.
If you purchase commercially sourced driftwood, you might find that they suggest different steps possibly involving just skipping right to the boiling part.
What if the driftwood still floats and won’t sink?
If after cleaning, soaking and boiling the driftwood, it still floats and won’t sink to the bottom of your aquarium, you can try a few other methods:
Bury the ends of the driftwood in stone or other substrate. If you have stone or another substance on the floor of your aquarium, you can often just bury or otherwise fasten your driftwood in it to hold it down. This is the easiest and quickest way to hold down anything in your aquarium.
Weigh the driftwood down. You can also try to weigh the driftwood down with another piece of heavier wood or another object in the aquarium. You might try to lodge one edge of the wood in a corner and weigh the other end down to hold it in place.
Fasten something to the driftwood. If you’re handy, you can drill small holes in the wood and attach a weight of some kind – a piece of slate or stone for example – to weigh it down. While some people often use a glue or other fastening substance, ensure you don’t use a toxic product that can leech into the water and harm your fish.
You have several options available to weight down your driftwood but you’ll often find that burying it in the stones at the bottom of your tank and/or wedging it against another heavier object will suffice.
Why is driftwood considered valuable?
Driftwood is considered valuable for various uses simply because some people are willing to pay for it. Driftwood is simply dead wood that has washed up on shore and has often alternated between being saturated with water and dried by the sun, depending on where it is found.
As such it has often been removed of its bark and has a weathered look and appearance that many people find appealing. Any wood that has survived this process without rotting, might be considered suitable for your aquarium.
While some driftwood can be found floating in the water, other driftwood has washed ashore and given the natural effects of the water, sun and other elements, has resulted in a unique piece that can be used in various applications such as furniture, as part of an art exhibit and of course at the bottom of an aquarium.
While you can find your own driftwood on a beach or near another body of water, purchasing it commercially saves yourself the time and effort of locating it yourself.
Why is driftwood often chosen to place in an aquarium?
Driftwood is a good choice for your aquarium for a number of reasons:
- Driftwood is generally easily found both commercially for sale in fish or pet stores and online.
- It can be privately sourced and collected from lakes or other bodies of water.
- It offers fish in your aquarium a place to hide which can reduce their stress levels.
- Driftwood can add a natural and aesthetic look to your aquarium.
- Adding a piece(s) of wood to your aquarium can offer benefits to the water in terms of lowering pH, helping to condition the water and even providing a food source for some fish.
While “driftwood” can take the form of various species of wood, it’s a piece of wood that has been conditioned to one degree or another by the environment (sun, water, etc) and thus can be suitable for an aquarium.
Summary
Driftwood can be an interesting and unique piece to add your aquarium that offers benefits to your fish and to your aquarium. While you can source your own driftwood, you might also choose to simply purchase it commercially instead.
You do have to ensure that the driftwood has been properly prepared before placing it in your tank however to avoid introducing disease into the water that can hurt or even kill your fish.
Properly preparing your driftwood before placing it in your aquarium does several things:
- Ensures that the driftwood is clean and doesn’t bring contaminants into the tank that can hurt or kill your fish.
- Removes tannins from the wood which can otherwise leech out into the tank’s water.
- Improves the wood’s ability to sink and not float which is what you want.
If you aren’t aware of how to prepare driftwood before placing it in your aquarium, check out my article called Can I Use Driftwood In My Aquarium? (Explained) to learn more.