Creating Aquariums that Reflect Fishes' Natural Habitats

Fish can be found in nearly every water system throughout the world. Even within these systems, their habitats are often altered throughout the year - sometimes very quickly, as in the case of abrupt weather changes. As a result, fish have evolved to cope with seasonal and environmental changes. It can be a particularly rewarding challenge to try and recreate some of their natural aquatic environments in your own fish tank. By matching fish, plants, and décor to those found in a natural habitat, you can succeed in bringing an authentic-feeling piece of the wild into your living room. You will also experience the pleasure of seeing your fish behave similarly to the way they would in nature.

There are two ways to approach building a biotope, or habitat-specific, aquarium. You can employ a strict method, faithfully recreating the natural environment with precisely those fish, plants, rocks, and décor that exist there. Or, you can represent that environment using the same general kinds of foliage and decoration without adhering to your natural model so strictly.

Either way, the first step is to educate yourself as thoroughly as possible about the particular fish that you want to keep. Remember that fish that exist within the same stretch of river, for example, may not peaceably coexist in a small tank together. They might have a predator-prey relationship, or be territorial. You need to know how well the fish you house will get along together, and also be aware of their habits, feeding preferences, and the places where they spend most of their time. Once you know your fish, you can then choose the plant life, décor, and equipment that will most faithfully reflect the natural environment that they live in.

Some fish tanks come equipped with an all-in-one setup that will have the appropriate heater, filter, and lighting system built right in. Be aware, however, that some biotope designs may call for special lighting, faster or slower filtration flow, and/or external filtration, and these pieces are difficult to alter in a built-in setup. Underground filtration usually works poorly for these kinds of aquarium designs, because large rocks can confound it and the water movement that it creates can stress plants. An external power filter is preferable. It's easier to clean and maintain, and it will allow you to control the flow rate inside the tank. Aquatic lights are made for specific purposes: some promote plant growth, while others showcase the colors of fish. Spotlights and underwater lighting can highlight hidden areas of your aquarium and produce unusual effects.

The substrate, which is the foundation of your aquarium, will support your plants as well as the wood and rocks that you add for décor. Substrate typically consists of pea gravel, which is available in coarse, medium, and fine grades. Sand poses problems, because it can either be compacted or else churned into the water by fish. Silver sand is sometimes desirable, however, for highlighting various features under the light. You can create a variety of atmospheres by mixing different grades and colors of substrates, although a fine grade is generally preferable for plants.

Rock varieties that are safe for use in an aquarium include basalt, coal, flint, granite, quartz, sandstone, and slate. Many others will alter to chemistry within the water. Make sure that the rocks you place inside are stable. To create a natural effect, make their placement look accidental. Spray-on rock is hardening foam that can be used to create interesting (though not completely realistic) effects. Again, consider your fish when deciding how to adorn their homes. Some algae-eaters need real wood (bogwood works well) as a part of their diet.

Other materials one can use when designing a biotope aquarium include bamboo (especially for a Southeast Asian swamp habitat), clay pots, twigs, snail shells, and a wide variety of synthetic décor.

Planting is done last, just before the introduction of fish. Choose plants that are of suitable size and shape for your aquarium as a whole and also create interesting contrasts between each other. As always, nature will be your model; but don't be discouraged if you can't completely replicate a natural habitat. In wild waterways, plant species tend to grow in clustered groups. If you have a plant that particularly stands out, place it centrally.