Wood is unique and offers amazing dimension to your aquascaping design.
This article is contributed by Aquariums Advice member Scott68TN
Driftwood is one of the most dramatic and aesthetically pleasing additions you can make to your home aquarium. Wood is unique and offers amazing dimension to your aquascaping design. Coupled with live plants you can have the best tank in town! Not only is it visually pleasing, but it also promotes a healthier tank by providing a good place for bacteria to grow. Wood lowers the PH for those who wish to do so naturally in a more stable manner than chemical additives. This Aquariumadvice.com article will try to cover the most common information needed to treat and use wood in its most appropriate manner. Lets begin with wood types and areas of harvesting.
Driftwood is a dead wood that has been adrift or stationary in the water for some time and may have washed ashore where it continues to wear due to wind sand and season. I usually find the wood I use on the beaches of the East Coast near the mouths of rivers or on salt marshes also known as mud flats. Wood that comes from salt water has the added benefit of being salt treated by the environment. This is not to say salt treated lumber is a good wood to use within the aquarium. Lumber from home improvement centers and lumberyards have been treated with poisonous salts, which will kill your fish! Sea salt will treat the wood in a natural way that your fish will appreciate. Salt-water driftwoods that have been well aged usually have very little tannins remaining and do not tan the water as much as wood found in a bog or other freshwater source.
Tanning is the process of releasing tannins into the water and turning it a yellow to brown color. A lot of people refer to this water as “black water”, which most Amazonian fish find comforting, as do some aquarists. River wood varies in its preservation and tannin content. As a side note, tannin used to be extracted from oak leaves to tan leather. Bogwood comes from bogs. A bog is water source that is replenished by rain only. Water from bogs is usually of poor quality and very acidic, but it is good for preserving wood. Since the water is stagnant and does not connect to any other water source, including the ground water table, a bog has very little oxygen or nutrients to support bacteria that would otherwise eat a tree away. Peat naturally comes from bogs and you may have seen peat additives being sold to the aquarist to aid in the spawning and health of soft water fish like Discus who are very particular about water. Bogwood is therefore very good for creating black water conditions and lowering the PH. All wood deteriorates over time, although hardwoods stand up a little better than, say, a pine, which I wouldn’t suggest for the aquarium. Many pieces found on rivers will end up being cedar since in a river there is usually no salt or lack of nutrients to eliminate the critters that deteriorate wood. Cedar is a good choice due to its natural ability to withstand water.
Wood from your local fish store should be specifically mentioned. This wood should be pre-treated and free of organisms but you have NO way of knowing. I would suggest a few easy steps to insure the health of your tank. Get a clean plastic container large enough to submerge the item.
Put your wood in it. Add a liberal amount of salt to the container: 1 cup per every 10 gallons of water should be sufficient. Soak it for a few days changing the water every day. This process should kill any surface bacteria and drive out any air as well as waterlog the piece, allowing it to sink. If the water continues to tan after the third water change, you have a stubborn piece and will need to soak it until it stops. That is the case if you do not want the black water feel in your tank, or do not want the acidic properties caused by tannic acid. I cannot predict the amount of time to soak a store bought piece but if the water is the color of tea after three days and three water changes it could take you from weeks to months to treat it. You may also boil it, as the heat will soften the wood and allow for the tannins to leach out quicker. When you boil wood it may smell a bit like tea or it may smell a lot like urine. All you can do is to hope for the tea smell! The tannic acid in tea is known for its anti-inflammatory and germicidal properties (i.e. tannic acid in tea helps with swelling). Black tea is the most effective. Lets not pour tea into our tanks just yet; the fish may not like the caffeine!
Treating found wood is a bit more time consuming and is riddled with conflicting systems, however there are a few ways to cure and treat wood effectively. The difference will be what tools you have at your disposal. Here are the basics:
Clean your wood. Chip off any loose bark or pieces, sand down any sharp edges that may harm fish. A power washer or hose with a good high-pressure nozzle does wonders on sturdier pieces Do not use soap of any kind. Some people have sandblasters that do a great job of cleaning up anything, but are not necessary. If the wood is not completely dead or dried up you will need to make this happen. Get a tub large enough to submerge the wood and fill with water. Add chlorine bleach at a 1:50 ratio and soak for the wood for a few days. This should kill most bacteria (many people do not like this step and would rather boil the wood for 8 hours, however some pieces are too large and by the time the wood makes it to the tank there will be no amounts of chlorine bleach left). After the bleach bath you can leave it in the sun for a good sun bleaching. After the initial bleaching you will no longer use the chlorine bleach bath. Instead, you can use salt for a mild but effective anti-bacterial treatment. You can purchase pure salt at your local home improvement center at about $2.50 for 50 lbs. Look for water softener and be sure its 99% salt. Add 1 cup per 10 gallons of water and start the long task of soaking for a week and drying for a few days until the wood is dead. This could take a season or two depending on the wood prior to starting. You are killing the living cells in the wood and salt-treating the wood at the same time this is necessary, as living cells equals food to critters and salt equals death. If there is bark it will be easier to remove after each weekly soak and dry. It will loosen more and more as the wood swells and contracts. If your wood is already dried and seemingly dead you can bleach once then start soaking in the salt-water solution for a few weeks changing the water every couple of days. There should be no need to keep soaking and removing the wood for the purpose of sun drying/bleaching, nature has already done this for you. Finish up by soaking in de-chlorinated water for a week or until the tannins are to a point you can live with before putting it into you aquarium.
Boiling is the preferred sterilization process. Some pieces are quite large and cumbersome to boil. If you insist on putting wood into your aquarium that has not been through some sort curing process, this is a must. You can build a bonfire in your yard or try a large pot on the stove. Be warned – I once broke the burner on my stove trying to soak a big piece. I always try to boil when I can but feel confident with the bleach salt method as well. To boil effectively you must do so for hours, which can be hot, humid, and smelly! I usually add salt to the water and boil for 7-8 hours.
Sinking your wood can be a challenge. Wood floats! A lot of people will say driftwood sinks. Well some driftwood sinks. It must be heavier than the water it displaces. Air must be driven out of the wood. Boiling drives air out but mostly time will prevail. I use bricks to weigh the wood down while soaking it. Eventually it will waterlog and sink. Some wood will never be heavier than the water and some wood will be about as heavy as water giving it zero buoyancy, meaning it may sink but it will be unstable or prone to move around. The easiest and quickest way is to put a piece of slate on the bottom and bury it under the substrate. Aquarium epoxy should be used but must admit I have screwed a few on with epoxy sealed screws. Slate is very easy to work with. You can break it up with a hammer, drill it with masonry drill bit and sand the edges. I use a Dremel for sanding and shaping.
Overall it looks like a huge chore to prep a piece of wood. Just keep the water clean of algae and bacteria while it soaks and that’s all it really comes down too. I’ve had a piece I salt treated that has been sitting on my back deck as a centerpiece for a year now. Eventually I will use it but it looks better as each month goes by.