I'd agree with not taking any old piece of wood from a woodland area. That said the vast majority of wood sold to aquatic shops which is then sold on to us comes from wooded areas not bogs. The 'root' is boiled in vats of water for about 4-7 days to remove impurities such as the tanins, the sap and the fertiliser you mentioned before it is sold on.
Driftwood Basics
by Alec Perseghin & Eric Glab
Driftwood is defined by Webster's Dictionary as "Wood floating in or washed up by a body of water". To the aquarium enthusiast, it is sought after and widely use for aquascaping. Driftwood can be an esthetically pleasing addition to the aquarium environment.
Types of driftwood
There more than several types of driftwood that are readily available for purchase in the aquarium trade. These include:
Standard driftwood - The most readily available and most economical kind of driftwood. This wood is commonly found in North America, besides other part of the world. It is the remnants of trunks or branches that are worn by water erosion or sandblasted by wind erosion. Standard driftwood is available in an endless number of shapes and sizes. It floats and can be sunk by two different methods. The first method is letting it soak in the aquarium over time. The length of time a piece of standard driftwood floats depends on the piece of wood. Small pieces can take weeks, larger pieces take months or even years! A much quicker method is to use a piece of slate that has a hole drilled into it for a screw. We recommend a stainless steel screw which won't rust in the aquarium. The screw is simply fit through the hole and then screwed into the wood. You can also use aquarium safe silicone, but you will have to wait for the silicone to cure. Once in the aquarium, the slate can be covered with either rocks or gravel.
African or Savanna Root - This is probably the second most common driftwood available. It is self-sinking, therefore no slate mounting or extending soaking is needed. It does not have the appearance of standard driftwood. Rather, it is gnarly on one side and quite smooth on the other.
African Driftwood - Not to be confused with African Root. African driftwood looks more like standard driftwood but it's self-sinking. It's more intricate in shape and darker than standard driftwood. Pieces can be quite hollow or have a ribbed appearance. African driftwood pieces are typically hundreds of years old. They command a high price when compared to standard driftwood.
Malaysian driftwood - Another self-sinking driftwood. Close in a appearance to standard driftwood, it typically has elongated branches. An excellent choice if you are looking to attach plants like Java Fern to a piece of wood. It is self-sinking.
Preparing driftwood
Since driftwood is a natural product that is usually found washed up on shores or laying on the ground, it's important that it is "cleaned". The easiest way to clean smaller pieces of driftwood is to boil it. Find a pot large enough to submerge the your piece(s) in (large soup pots and lobster pots work well). Place the wood in the pot and bring to boil for about 15 minutes. Drain the water out of the pot, refill it and repeat. After the second boil fill the pot one last time, boil this for another 10 minutes. Let it cool off, drain and your done. Of course, larger pieces of driftwood will not fit in a pot, so boiling water will not be practical. The next best thing is to scrub the driftwood using hot water. A potato brush works rather well and they are usually available for a couple dollars at your local grocery stores.
African Driftwood African Driftwood
What driftwood does to water
Boiling driftwood will have remove much of the tannins contained in the wood. What are tannins? Tannins are a natural compound contained in the driftwood and they are released into your tank water as the driftwood soaks. Tannins will stain your tank water a light yellow color or when concentrated - the color of tea. The amount of staining depends on what type of driftwood and how much wood driftwood you are using. Boiling driftwood can be thought of as placing a bag of tea in a hot cup of water. The longer the tea is in the water and the hotter the water is, the more tannins that will be released.
Soaking driftwood in a container will also help release the tannins before it is introduced into the aquarium. This process can take quite a bit of time. It can be weeks or even months before most of the tannins are released.
In all plants and trees, tannins are used as defensive compounds that counteract bacteria and fungi by interfering with their surface proteins. There are rivers in the Amazon that are so filled with tannins that the water is stained to the color of tea and very few organisms can actually thrive in this water. These rivers are called "blackwater" habitats. It just so happens that many fish from the "blackwater" habitats of the Amazon seems more susceptible to disease. Coincidence? We don't think so.
African Root African Root - close-up
The most common question most cichlid keepers have about driftwood is "how will it effect my pH?" Answering this question is not easy, but there are a few things to consider. Since driftwood contains tannins (which is also referred to as tannic acid) it will try to lower your aquarium's pH. Your pH may drop if the buffering capacity of your water is low (low mineral content). If the buffering capacity is high, the chance of a piece of driftwood causing a pH swing is minimal.
Driftwood will also tend to soften your water. This is great if you are keeping softwater fishes like Discus, Satanoperca daemon or Uaru Fernandezyepezi. It's not so good if your water already has a low buffering capacity and you are keeping fishes from Lake Tanganyika.
What's that fuzz on my driftwood?
Quite often after driftwood is added to an aquarium, a white almost transparent fuzz will grow on it. This fuzz can appear several weeks to several months after the driftwood is added to the aquarium. Popular thinking is this fuzz is either a fungus or a mold. Either way it's harmless, unfortunately it's not pleasing to look at. Some people have had luck just brushing it off. Others have had luck by introducing algae eating fish, as they will actually eat it. Neither technique will guarantee preventing this fuzz from recurring. The important thing is to have faith, as it will eventually disappear.
Conclusion
Without proper preparation of your driftwood and understanding the water requirements of your fish, driftwood can do more harm than good. But when properly prepared, driftwood can be a wonderful addition to your tank and make you look like an expert aquascaper!
