Mary Allen
Caring for houseplants is an art in itself – but aquarium plants? For many people, the question of planting in an aquarium is secondary, if at all. Only when the tank size and the fish species have been determined do thoughts begin to revolve around the equipment. Plants in the underwater world play an important role. In fact, they should move into the tank before the fish, making it livable and attractive. But what do aquarium plants actually need to thrive?
First planting in the aquarium
In an aquarium, the plants take on several tasks at the same time. They are like a natural filter: They clean the water, enrich it with oxygen, and can even absorb various toxins such as ammonium and nitrate, which get into the water from the fish left behind, or convert them into harmless substances.
At the same time, they offer the inhabitants of the underwater world sufficient protection, retreat options and natural camouflage. This is the only way for fish and other animal species in the aquarium to live out their species-appropriate behavior and feel comfortable.
In addition, the planting is also extremely decorative. When choosing the plant species, the main focus should still be on their mode of action. It is only with their help that the water basin becomes a real ecosystem and thus an aquarium that can be lived in.
Which plant species are suitable?
Not every underwater plant is suitable for every aquarium. Depending on the size of the tank, the water properties and the animal species that are to move in, you have to pay close attention to which plants are suitable. Factors such as light sources and temperatures also play a crucial role. They ensure optimal conditions for photosynthesis and thus for oxygen production.
Plants that die after a short time because they were unsuitable end up having the opposite of the desired effect: they poison the water through their putrefaction processes.
At the same time, when planting for the first time, it should be noted that no real forest overgrows the pool. The plants would hinder each other, fill the tank excessively and give the fish too little freedom to swim. It is therefore always advisable to use a combination of fast and slow-growing plants.
However, the diversity of species should not be exaggerated. It is better to only use three to four species and several plants of these instead of ten different species, one each. Visual chaos aside, aquarium plants like the Vallisneria prefer to be planted in groups.
The most popular aquarium plants are preferred primarily because of their easy-care handling. They include, among others:
- Vallisneria, also known as water screws: These are fast, long-growing freshwater plants that require a lot of light. They look like grass, have long, thin leaves and grow to the edge of the pool. They have to be regularly shortened or sorted out in order not to take up the entire pelvis.
- Sumatran ferns: They are fast-growing and relatively undemanding freshwater plants with medium to high light requirements. Your big advantage: They reduce the formation of algae because they process most of the nutrients themselves. At the same time, they are also suitable as free-floating floating plants and can be described as bushy due to their slender and diversified growth habit.
- Elodea, also called waterweed: This refers to the fast-growing freshwater plants that make high demands on a lot of light, but can be very persistent. They grow branched with bushy leaves.
- Southern Leaf: It looks a bit like clover. Bacopa grows quickly and covers a large area, so it is well suited for stone plantings and has a medium to high light requirement. However, it can also get quite high and should be shortened accordingly on a regular basis.
- Carolina Water Mermaid: This fast-growing plant also thrives in freshwater, does well in groups, and requires medium to high light levels. With its fine leaves, it almost resembles a coniferous plant.
- Cryptocoryne, also known as water goblets or water trumpets: They are slow growing but persistent and they are viable both above and below water. They also belong to the freshwater plants and form cup-shaped foliage.
- Echinodorus or sword plants: These slow-growing freshwater plants fan out quite widely, have oval-shaped leaves, and can sometimes take on very beautiful, reddish hues, which makes them look almost like leaves.
- Anubia, also known as spear leaf: Anubia is slow growing with at least medium light requirements. Originally it was a marsh plant, but now it also thrives in freshwater aquariums. She feels just as comfortable in gravel as on stones and wood.
- Mangroves, algae, seaweeds, corals: they all belong to saltwater plants and therefore need special conditions in order to thrive optimally. In addition to the typical salt content, they sometimes need special fertilizers, a different grain size as substrate, and last but not least a lot of light.
Artificial aquatic plants
Again and again aquariums are equipped with artificial plants. Not only is the natural filter effect lost, but the overall balance in the “aquarium” ecosystem is not getting the support it needs.
To compensate, technical devices are used, which – also artificially – are responsible for the oxygen content and clean the water. Artificial aquarium plants actually have a few advantages:
- You don’t need any maintenance.
- They can neither rot nor get sick.
- They still provide protection and camouflage for the fish and other animals.
Nevertheless, an artificial plant will never look as natural as the real thing. They are mainly used for decorative purposes, for example to beautify the perhaps still thin stock. Or they have to be used as a substitute for sick fish so that they don’t poison themselves with the “normal” plants.
Sometimes the artificial plants should simply bring some color into the water basin. For example by placing them in a freshwater aquarium in the form of artificial reefs. There are hardly any limits to the design ideas. However, the welfare of the fish should always have priority. For species-appropriate husbandry, they depend on appropriate planting.
Care of the aquarium plants
Basically, the aquarium is set up starting with the substrate (including long-term fertilizer), sand, stones and caves, and other decorations. The water supply follows gradually. The plants are only used when they are sufficiently filled, and with caution: Depending on the type of plant in question, the background, the sides or special levels should be chosen as the location. It is important that the substrate is well-prepared to provide the roots with sufficient support. The long-term fertilizer provides the plants with all the important nutrients right from the start. After about four to five weeks, the biological balance in the aquarium will stabilize.
For planting it is usually sufficient to press a small hollow in the gravel. The roots are first carefully shortened so that they will grow back stronger later. Then the plant is placed in the trough and covered with gravel again. Aquarium plants are not exposed to strong weather or strong currents. Nevertheless, the substrate should not be too fine-grained.
In addition to sufficient support, an optimal supply of nutrients and ventilation for the roots are essential. Aquarium gravel with a grain size of approx. 3 to 8 mm is usually the best choice. The gravel should also be as light in color as possible so that the roots still get enough light.
Some exceptions even grow primarily on rocky ground and not in gravel. These plants can be adjusted with a thin thread on the rock until the roots have dug in sufficiently.
Water parameters and fertilization
To ensure the nutrient supply, the water parameters should be checked regularly. In particular, the PH value, the iron content and the oxygen or CO2 content must be checked.
If necessary, you can help with liquid fertilizer or so-called bio-CO2 sets. However, the aquarium enthusiast should have a certain understanding of the biological and chemical processes in order to take the right measures at the right time.
For example, many plant species only prefer soft water. The water should also be changed at regular intervals to aid in cleaning. This benefits the fish and the plants alike.
The Underwater Nursery
Similar to a vegetable patch, underwater plants also need to be cared for. Remove leftovers that have fallen off and shorten shoots that grow too quickly. This should ensure the ideal light supply.
Artificial light sources are to be preferred, not least because of the fish’s love of natural sunlight. This means that the aquarium does not have to be right next to the window, and therefore in a draft, and the temperatures can also be better regulated. After about a year of use, however, the fluorescent tubes should be replaced. Barely visible to us humans, the luminosity decreases after about this period of time and photosynthesis suffers from the lack of a spectrum of light sources.
Under optimal conditions, many plants will begin to sprout on their own. These can also be cut off and removed or grown as new plants.
On the other hand, if the leaves turn yellowish, brown or generally pale, this could be a sign of nutrient deficiency or excess. However, by checking the values and fertilizing if necessary, such occurrences can be easily controlled.
It becomes more difficult with parasites. Snails, freshwater polyps and other unwanted guests can pose a threat to the planting. Snails are usually easy to collect, but with other pests it often only helps to temporarily quarantine the infested plant or, if in doubt, to remove it entirely.
Blue-green algae, for example, form a veritable layer on the leaves and thus impede the plant’s photosynthesis. They also release toxins into the water, which in turn harm the fish. In such cases, thorough soil and water care is required. Sometimes it helps to leave the aquarium unlit for a few days. However, the health of the fish and plants must be taken into account in such measures.
Compatibility with the aquarium inhabitants
When selecting the aquarium plants, the future occupation should be taken into account. Breeding may require special spawning hiding places, such as the Sumatra fern offers. It is also very suitable for small shrimp. The Elodea (waterweed), on the other hand, is not recommended for shrimp at all.
In contrast, cichlids tend to nibble on numerous plants. However, the Anubia usually leave them alone.
Size, number and direction of growth (flat, wide or particularly tall) should also match the animal species. Not only fish have their special requirements for aquarium plants, but also reptiles and even the plants themselves.
Change of plants in the aquarium
Ideally, the aquarium is always a coherent system. The smallest fluctuations, irregularities or disturbances can throw the entire biotope out of balance. Much like the water needs to be thoroughly prepared, controlled, and renewed, so too does the need for careful attention to the planting. Each component is directly dependent on the other. Be it the fish, the technical aids, the water values, the equipment, or the aquarium plants.
When does an aquatic plant need to be changed?
Only a few commercially available aquatic plants are annuals. Most easily last for several years. They multiply themselves, for example by sinkers, they are content with the light conditions and fertilizers and a little care now and then.
Only when a plant is actually so badly damaged by a lack of nutrients or severe parasite infestation that it is more of a burden than a relief should it be replaced.
On the other hand, the fish in the planting can be planted so drastically that it only makes sense to dispose of the affected plant. Such problems usually arise because the plant species was not chosen to match the fish population.
Loose, floating plants that may not have been rooted firmly enough or may have been torn out by the fish can be replanted fairly easily. At least as long as the roots are not too badly damaged.
The general rule, however, is that aquarium plants should remain as unchanged as possible so as not to disturb the biological interaction that has once taken place. If necessary, they should therefore be replaced by equivalent plants.
However, reasons for changing the planting can also be other factors in the tank that change and have to be compensated for by new plants. Spawning times are often such a reason. Other conditions in the aquarium are sometimes required for courtship display, spawning, and the rearing of the young. A change of plants can also make sense if a new resident is added or, conversely, some are removed.
Do aquarium plants overwinter?
Unlike in the garden pond, the aquarium is normally subject to permanently constant conditions. However, some use both options for keeping fish for their aquaristics. For example, goldfish or koi spend the summer in the garden pond and are placed in the aquarium to overwinter.
However, this does not necessarily mean that the pond plants have to move with them. On the contrary: In order to optimally care for plants and animals, the pond plants should remain untouched so that they can thrive again naturally in spring.
Instead, suitable plants must be prepared in good time for the winter quarters in the aquarium. As a rule, the affected fish hibernate in slightly cooler temperatures and in dark rooms. The planting should be able to get along accordingly undemandingly. Some pet owners even do without aquatic plants during the winter. However, species-appropriate behavior includes many opportunities to retreat, especially during this resting phase.
In addition to caves, protective plants are the best and just as natural option for fish to feel protected and safe.