There’s a reason why aquaristics is one of the most beautiful and versatile hobbies. You can observe a small ecosystem up close, learn about the behaviour of the different fish species, and marvel at their exotic colours. There are also many opportunities to implement your own design ideas when setting up your aquarium.
First steps
The freshwater aquarium
Among freshwater aquariums, community tank is the most common. In this tank, various mostly tropical ornamental fish species and different plants are kept; these are all similar to each other in their requirements. A species tank, on the other hand, is home to fish of one or more closely related species (e.g. mbuna cichlids).
Equipment check-list
- Aquarium with cover and fluorescent tube
- Aquarium substrate (e.g. polystyrene board (approx. 0.5–1 cm thick) or soft rubber)
- Substrate
- Decoration: rocks, aquarium root, and water plants
- Filter: Internal or external filter with filter substrate
- Regulator heater and aquarium thermometer
- Magnetic disk cleaner or sponge (special) to remove algae
- Water conditioner and filter bacteria
- Hose for water change
- 10-litre bucket used exclusively for aquarium maintenance
- Timer for aquarium lighting
- Feed, suitable for the chosen fish species
The right location
The aquarium should be set up in such a way that you can watch the fish from a comfortable place. However, direct sunlight can promote algal growth and heat up the water too much in summer. It is therefore better not to place the aquarium too close to the window. Especially for larger tanks, the load-bearing capacity of the location must be considered in the planning. Even small tanks have a considerable weight: One litre of water weighs 1 kg – plus substrate, stones, and other decorations. This can quickly add up to more than 80 kg. The safest place for an aquarium is therefore on a special aquarium base cabinet, which takes into account this weight in the static structure. The aquarium should be placed on a polystyrene base or other special base. This will compensate for any minimal unevenness of the storage surface.
Furnishing the aquarium
The purpose of setting up the aquarium is to create a species-appropriate habitat for fish and plants. The desired “biological balance” depends on the interplay between fish, plants, water, and micro-organisms as well as the technical equipment.
The most important steps at a glance
1. substrate and decoration
Mix about one third of the substrate washed with clear water (no turbidity should remain in the water when rinsed) with some nutrient medium, and spread it evenly on the bottom of the tank. On top of this, add the remaining substrate. The bottom of the tank should be covered with approx. 3–6 cm of substrate rising towards the back. All decorative objects such as stones and roots are scrubbed off with clear, hot water and pressed into the gravel. For fish that rummage through the substrate, make sure that the structure stands firmly on the aquarium floor and that nothing can tip over (fix with silicone if necessary). For such animals, a round-grained substrate is also preferable. The tank is then filled about one third full with tempered tap water, which has been prepared beforehand to suit the fish. Depending on the needs of your future fish, the water values must be checked regularly.
2. inserting the aquatic plants
Before insertion, remove the plant substrate adhering to the roots and shorten the roots of the plants by about one quarter with scissors. Fast-growing stem plants (e.g. hair nymphs) are excellent as background plants. Press them into the substrate, and weigh them down with a pebble. In the middle area, single rosette plants growing in width (e.g. the Amazon sword plant) look particularly beautiful. To plant, simply bore a hole in the gravel with your finger and place the plant inside. To avoid blocking the view of the fish, only small-growing plants such as the small spear leaf should be used for the foreground. The perching plants also look quite decorative in the foreground. They are attached to stones or roots with a nylon thread, which can also be used to tie in java fern, among other things.
3. attach filter and heater
Note: Always unplug technical equipment before reaching into the water! Now fill the aquarium with prepared tap water up to about 3–4 cm below the rim. Then attach the control heater with suction cups in one of the rear aquarium corners. In the other corner, attach the internal filter filled with filter material or – if an external filter is used – the intake pipe. The corresponding outlet is mounted horizontally at the height of the water level on the rear aquarium pane or on the side. The thermometer is mounted on the front or side of the aquarium in order to be able to check the water temperature at any time. Most tropical ornamental fish species prefer temperatures around 20–28°C. Ask your pet shop about the more exact needs of the particular fish species.
4. start-up of the aquarium
After all technical devices have been connected, the cover can now be carefully placed on the tank. The filter, heater, and lighting are then connected to the electrical circuit. A timer ensures a regular lighting period of 10–12 h.
5. run-in phase
Important: The fish should be introduced only after a “run-in phase” of about 3–4 weeks. During this time, the valuable micro-organisms are formed in the filter mass as well as in the substrate. They take care of degrading pollutants and the biological balance in the aquarium. This process can be effectively supported by “inoculating” the filter mass with filter bacteria.
6. selection of fish
After 3–4 weeks of the run-in period, a suitable habitat for the fish has been created in the aquarium. The following must be taken into account when selecting the inhabitants:
- The fish species must match in their behaviour as well as their water quality and dietary requirements.
- The water values can be checked with a test kit from the pet shop (for more information, see “Fish-friendly water treatment and partial water changes”)
- Each fish species lives in a preferred water region. The aquarium appears most lively when the upper, middle, and lower water regions are inhabited.
- As a guideline, a maximum of 1 cm of fish per 4 l of water is recommended. A more densely populated tank tends to cause fluctuations in water values, over-fertilization, and increased algae growth and thus carries an increased risk of disease for the fish.
7. placing the fish in the aquarium
The ornamental fish should be introduced carefully in order to avoid a “transfer shock”. To adjust the temperature and water conditions, the transport bag should first be placed in the tank. No water should flow in or out, and care must be taken that the bag is not placed under the lights. After about 15 minutes, one third of the transport water is replaced with aquarium water or topped up accordingly. This process is repeated twice after each additional 15 minutes. Then carefully place the fish into the aquarium with the help of a catch net. Because the transport water may contain medications and micro-organisms to which the small aquarium ecosystem is not adapted, it should definitely be discarded.