Driftwood

Driftwood can be a great addition to your aquarium, if it has been gathered and prepared correctly. NEVER use wood cut straight off a tree. Native wood which has been washed up on the beach is the best. Freshwater bacteria will have a hard time surviving after having been pounded about and thoroughly soaked in salt water. The darker woods, like rata and rimu, blend well with dark gravel and provide a beautiful backdrop for plants. Good places to find these native bits are the west coast beaches, especially near river outlets. Watch out for nearby sewer pipes or other polluted areas. Other reasons for choosing dark wood are;
It is more dense than light coloured wood so will last longer in an aquatic environment.
It is more likely to already be waterlogged so will immediately sink in the aquarium without having to be soaked for weeks first, or be anchored down with silicone or rocks.

Some fish, such as bristlenoses, Ancistrus, require a steady amount of wood in their diet to aid digestion. They will also use the holes and hollows in the logs as breeding sites.

Gathering river wood is not such a good idea as it may have bacteria or parasites in it which are not compatible with an aquarium. A thorough and prolonged boiling of the wood will kill most undesirables though if you want to take the chance.

When selecting pieces of driftwood, always bear in mind the size of the tank they are meant to be decorating. It is easy to get carried away with a log which ends up being too large for the aquarium. Of course if you have a large outdoor container, such as an old bath, you can fill it with water and keep your spare driftwood waterlogged until needed. Look for the interesting shapes which are found at the lower tide levels. These pieces have washed down the rivers, are well weathered, usually totally waterlogged, and have been soaking in salty water. Make sure they are not rotten. Give them a good poke with a stick, screwdriver (which you just happen to have in your pocket) or other sharp object and check for spongy areas or bits flaking off. These are signs of rot and such pieces need to be discarded. If you are looking through driftwood lying above the high tide level, watch out for katipo spiders.

When I go looking for driftwood I do it on a large scale and choose lots of pieces in one trip (because the beach I like to search is 4 hours away. If you ever visit Hokitika, take a walk along the beach, it is a treasure trove of interesting native driftwood). Rather than carry my booty along the beach, I put it in a pile with an upright stick beside it so I can find it later on my way back to the car - and preferably not too far from the car either! Remember that waterlogged wood is a lot heavier than the dry stuff so don’t get carried away with collecting large pieces.

When finding a piece you think might be suitable, study it from all angles. Which side is most interesting? Which way up should it go? Is it long and smooth, so suitable for using as a support wall to hold up terraced levels? Has it got great curves and lines to make a dramatic centrepiece? Too long? You can chop off an end, assuming the chopped end cannot be seen. Cutting the end on an angle so it fits snugly against the end of the tank helps to keep it in place.

Once you have chosen your driftwood, what has to be done to it? Clean it thoroughly. Wash it while still at the beach to remove as much sand as possible. Once home, scrub your log thoroughly with a wire brush, or nail brush. An old toothbrush (or that screwdriver) is good for getting into the smaller nooks and crannies. A final squirt with the hose and your log should be ready to use. It might also pay to soak it in a container for a week or two to check if any tannins are still being released. These are harmless to your fish but will discolour the water.

If the wood is not fully waterlogged, so still tending to float a bit, weigh it down in a container. A brick or rock is useful for this. Hold the log down with the brick and totally cover it with water. It can take many months to totally waterlog some pieces, which is why it pays to choose those already sodden. Drilling a few holes where they won’t be seen will speed the waterlogging process up. So will using warm, rather than cold, water. I seem to remember being told adding baking soda to the water will hasten things along too. Something to do with the soda removing excess air bubbles so saturating the wood more quickly, but I am not too sure of the particulars.

If you don’t want to wait until your log is fully waterlogged there are a few ways around it. Silicone the log to a large piece of perspex. When dry, lie the perspex on the bottom of the tank and then cover with gravel. Don’t lie flat objects (like perspex or slate) on top of undergravel filters as it will kill the underlying bacteria. You could also lie the perspex flat against the side, or back, of the aquarium. Another way is to arrange the décor so a large rock is anchoring down the log, either by lying on part of it, or by tying the log to the rock with fishing line. You could also silicone the log to a rock but make sure the silicone can’t be seen, and the arrangement looks natural.

Have you thought of sawing a piece of wood in half, lengthwise or sideways, and siliconing the flat side directly to the back, or side, of the aquarium? This allows more scope in the aquascaping department. Looks effective too.

Logs add a lot of interest to an aquascape and may be used purely as décor, or as shelter for fish, as food (the wood for Ancistrus and the resultant algae for herbivores), as a base for egglayers, and for plants to take root.

Plants can be attached to logs by sliding their roots into cracks, or by tying them down with fine fishing wire until the roots take hold. Java fern, Microsorium pteropus, loves attaching to wood, so does Java moss, Vesicularia dubyana. The moss can be wrapped around a protruding branch to hold it in place until the roots have attached themselves.

A word of warning here...make sure any holes in the log - either natural, or ones you have drilled beforehand - are big enough for fish to get in AND OUT of easily. Most fish cannot swim backwards so find getting out of holes and caverns a lot more difficult than getting in. Suckermouth fish can use their mouths to edge themselves out of tight places but other fishes have to be able to manoeuvre their fins.

How you use driftwood to decorate your aquarium is a matter if taste but don’t forget a small piece, well placed, can be just as affective as one which takes up more space.

Happy aquascaping!
- Caryl Simpson