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Fish are less stressed and seem more outgoing if they have areas to retreat when they need to — but be careful what you put in your tank. |
Driftwood
Driftwood (also known as bogwood) is widely available at aquarium stores. There are several varieties. Malaysian driftwood is interestingly shaped, dark and dense enough to sink even when dry. Unless pre-soaked, though, this driftwood will release amber-colored tannic acids into aquarium water. These will eventually peter out and disappear with regular water changes, but if you prefer, repeatedly soak and drain the wood for a couple of weeks before introduction to your aquarium to minimize the effect. Other types of wood available are Mopani wood and sand-blasted grapevine. Some types require prolonged soaking before they will sink. Some of these otherwise-floating woods are available cemented to a stone or piece of slate so that they will sink immediately.
One or more pieces of driftwood in your aquarium will provide small crevices and caves for a variety of species, such as shrimp, kuhli loaches and many species of catfish. They also serve as anchors for hardy plants, such as Java fern, Java moss and Anubias. Another reason to keep driftwood is that many suckermouth catfish, such as bristlenose plecos, appear to require small amounts of wood in their diets to remain in peak health.
It is possible to collect your own driftwood for your aquarium, but there are several potential problems. In some areas, collection may be restricted by law. “Wild” driftwood may bring pathogens, parasites or predators into your aquarium. Additionally, driftwood that you find yourself may introduce natural toxins or manmade pollutants into your aquarium. Those who do collect their own driftwood often boil it first to minimize these risks.
Rocks: A Weighty Matter
Usually, rocks purchased at an aquarium store are safe, but they should still be rinsed well before use to dislodge fine particles and/or dirt. Rocks you collect yourself may be perfectly suitable; on the other hand, they may contain calcium, heavy metals or other minerals that can wreak havoc with your water quality — and in severe cases, poison your fish. In some areas, rock collecting may be regulated or prohibited by law, so make sure to do research before you collect your own. When in doubt, purchase your rock from a reputable aquarium store.
Even moderately sized rocks are quite heavy, so be careful when situating them in your aquarium. Glass aquariums are quite strong and capable of supporting the weight of most aquarium rockwork if it is carefully placed and supported; it is wise to make sure that the weight of each rock is evenly supported. You can do this by situating the rock on a cushion of substrate, such as gravel or sand, which helps distribute the weight of a rock over a wider area. This can, however, create a “dead spot” in the substrate that is unreachable by a gravel vacuum unless the rockwork is moved.
An alternative that I have used requires some advanced preparation. First, determine which parts of the rock will rest on the bottom of your aquarium. You can do this by setting the rock on a piece of paper placed on a level surface. The contact points of the rock will leave visible indentations in the paper. You can then note where these points are and apply a generous dollop of silicone sealant to each of the points on the rock. Once the sealant has cured, the rock may be placed in your aquarium, and the blobs of sealant will function as cushions.
If you stack your rocks, do so carefully. Precariously balanced rocks may look attractive, but they may unexpectedly topple, due to human-caused vibrations, a sudden movement by large fish or even by seemingly innocent digging in the substrate. It goes without saying that this can have disastrous results for your fish, your aquarium, your floor and your relationship with any other individuals financially responsible for that floor. With a little planning — preferably prior to introducing the rocks into your tank — fairly stable rock formations can be produced. For even more possibilities, extremely strong epoxies and aquarium glues are available, some of which can even be applied underwater.
What About Seashells
Seashells have an undeniable appeal for many people, but they are not good additions to most freshwater aquaria. Even if you are sure they are clean and free from particles of the original inhabitants, they tend to leach minerals into the water, making it quite hard — to the point of being unsuitable for many fish. One notable exception to this rule is a dedicated “shellie” (Tanganyikan shell-dwelling cichlid) tank. These diminuitive cichlids’ lives center around snail shells, which not only provide a refuge and spawning site for the fish, but also help recreate the hard and alkaline conditions of their native Lake Tanganyika.
Territorial Markers
In nature, many fish use visual boundaries, such as rocks, plants or driftwood as territorial boundaries. The dominant of two cichlids, for example, will often decide that the entire tank is his/her territory when in a bare tank. That fish will then defend it to the detriment (and often death) of the subordinate individual. That same dominant fish in a tank with plenty of rocks, plants and/or artificial caves is much more likely to decide to set up shop in one area. It will defend that area fiercely but will not as doggedly pursue the subordinate fish past the boundary defined by, say, a particular rock.
It is a good idea to include plenty of extra hideaways in a tank of territorial fish. If there are more fish than retreats, the more subordinate fish in tank are likely to end up with nowhere to go. In some cases, such fish may even be killed by more dominant individuals.
Home Sweet Home
Providing your fish with the appropriate hideaways is a win-win situation. Your fish get a more comfortable home. You are rewarded with a more attractive aquarium with fish that exhibit a more natural range of behaviors, providing you with hours of fascinating fishwatching — and that’s what it’s all about, isn’t it? Back to Page 1>>
References
“Driftwood/Bogwood” (forum posting). www.thekrib.com/TankHardware/ driftwood.html. Accessed December 3, 2007.
Pederson, M. “Desktop Cichlids: The Shelldweller Recipe.” cichlidrecipe.com/ shellweb. Accessed December 3, 2007.
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