Features of acquiring aquarium plants.
Aquarium plants originate from all parts of the world with various climatic conditions. Some of them live underwater in riparian conditions, others on the border of land and water, in damp soil or shallow reservoirs. There are mosses, ferns, and higher flowering plants. However, they all share a common feature — the ability to adapt to the surrounding aquatic environment. Almost within every genus of aquarium plants, there are both easy-to-keep and more demanding species.
Before buying plants, carefully read the descriptions of individual species. Otherwise, you run the risk at some point of facing the fact that your acquisition is too large for the aquarium or unable to coexist with certain species of fish. Here, too, you should pay attention to what you buy. When choosing plants for a decorative aquarium, you must consider their appearance, habitus, size according to the required area and height, number of leaves and their “transparency” (light penetration to the lower layers and the ability to observe plants located behind depend on it), combination of color and shape with neighboring plants, and growth rate. Many plants that you can purchase may be imported or simply grown in conditions very different from your aquarium.
You should acquire young plants as they take root more easily. The plant must be healthy: stem without cracks, leaves without unhealthy yellowness, roots fresh — white, brownish, black in some ferns. Old leaves may show some degradation, but this is not critical. Large specimens adapt to a new planting site harder and slower than medium-sized ones. Very small specimens should be taken only if it is a rare species, and they require special attention. You must be prepared for the fact that some specimens of the plants you purchased will require an adaptation period, or even rehabilitation, and may completely drop their leaves and grow new ones.
Plants with finely dissected leaves — *Ceratophyllum*, *Cabomba*, *Limnophila*, *Myriophyllum* — need clean, transparent water, as aquarium turbidity easily settles on their fluffy leaves, giving them an unkempt appearance. There are currently over 50 species and breeding forms of *Echinodorus*. Some resemble small lawn grass (Echinodorus tenellus), while others grow up to 1.5 m in length (*Echinodorus grandiflorus*) and are too large for home aquariums. All *Echinodorus* prefer a nutrient-rich substrate and relatively warm water — not lower than 22°C.
Another large group of aquatic plants that attracts the attention of aquarium hobbyists is *Cryptocoryne*. *Cryptocoryne* species are thermophilic, with an optimal temperature of 25–27°C. They are subdivided into plants with aerobic roots (e.g., *Cryptocoryne crispatula*, or *balansae*) and anaerobic roots (Cryptocoryne griffithii). Aerobic roots need an oxygen supply for normal development, whereas oxygen is contraindicated for anaerobic roots. *Cryptocoryne* with aerobic roots grow on pebble substrates in small rivers and streams with flowing water. Species with anaerobic roots are better suited to a swampy, muddy bottom where oxygen penetrates with difficulty and in very small quantities.
If you plant a *Cryptocoryne* with aerobic roots in a muddy substrate, they will soon rot, and the plant will float to the surface. The same will happen if you try to root *Cryptocoryne griffithii* in the flowing substrate of a double-bottomed aquarium. Water ferns (*Microsorum* and *Bolbitis*), water mosses, and *Anubias* do not need rooting. It is enough to attach them to a piece of driftwood or a stone using synthetic thread.
However, the volume of planting depends on the type of fish. Among them, there are those that suit dense thickets (labyrinth fish). But for open-water inhabitants that need space for swimming, you should densely plant only the distant corners, while near the side walls and at the back of the aquarium, plants should be placed in separate groups. At the same time, you should choose plants that release a lot of oxygen. Schooling fish with light signals require a shaded location at the back of a densely planted tank.
If fish dig up roots heavily, it is best to place the plants in pots or leave them floating; if fish dig in the substrate (goldfish), you should avoid plants with thin feathery leaves, as they easily get dirty. Territorial fish often use large plants as visual landmarks when delimiting spheres of influence or simply define them as their property. Cichlids and harlequin rasboras, as well as a number of other fish species that eat tender greens, should not be kept in the same aquarium with plants, unless, of course, you are going to provide them with such expensive food.
Fish breathe oxygen and exhale carbon dioxide, which plants consume during the day in the process of photosynthesis, releasing oxygen. Plants play a major role in maintaining the required amount of oxygen. Different plants supply different amounts of oxygen. If the ratio of plants and fish in the aquarium is chosen correctly, both gases are sufficient for them, and they feel great. Planting density is also affected by the types of plants placed in the aquarium and their quantity: in an aquarium with a small number of slow-growing plants, too many fish will lead to the plants not having time to consume all incoming nutrients, disrupting the biological balance and leading to an increase in nitrate and phosphate levels, which in turn causes algae growth.
The number of fish must precisely match the ability of all plants in the aquarium to process fish waste products. The size and number of fish should by no means dominate over the plants. Look at your aquarium — if you mostly see fish rather than a “fish garden”, they are too large, there are too many of them, or they are too bright (or do not match in color) for this aquarium. If there are few plants and many fish, the latter experience an oxygen deficiency, and in this case, the aquarist resorts to aeration.
When choosing plants, you need to understand that many of them in nature grow at a depth of no more than 30 cm or even in damp soil occasionally flooded with water. Accordingly, you will not be able to grow everything in a deep aquarium. An important factor for plants is the depth of the aquarium. Some of them (*Echinodorus osiris*, Echinodorus uruguayensis, *Cryptocoryne parva*) do not grow well at great depths, especially in the small sprout stage. In natural conditions, such plants are found only in shallow water bodies. Conversely, some species (*Cryptocoryne aponogetifolia*) do not grow at shallow depths or transition from an aquatic form of existence to a marsh form (a number of large *Echinodorus*, *Sagittaria*). This is especially noticeable with improper aquarium lighting or an unfortunate location relative to natural light sources.
When choosing aquarium plants, it is imperative to ensure that the conditions in the aquarium correspond as closely as possible to natural conditions. If there is no such correspondence, the plant will get sick and eventually die. Unfortunately, even experienced aquarists do not always follow this rule. Every water plant enthusiast faces the problem of how to combine completely different hydrophytes in a single aquarium.
Most reputable tropical companies that grow hundreds of thousands of aquatic plants for sale widely apply the latest achievements of modern science. At the same time, their main task is to reduce the costs of plant cultivation while maintaining their best commercial appearance and durability during transportation over thousands of kilometers. Many species of these plants are grown in the humid atmosphere of greenhouses. The reasons for this are solely the slow growth of plants in a submerged state and the difficulties with their mass propagation. The appearance of such plants often changes beyond recognition, and they require a rather lengthy adaptation to aquarium conditions, during which aerial leaves die off and are replaced by new ones adapted to existence in the aquatic environment.
As soon as a plant enters conditions different from optimal, it freezes for a while due to stress, then rapidly degrades and, if the cultivation conditions do not meet optimal requirements at all, soon dies. In the conditions of the global aquarium trade, aquatic plants in excellent condition reach the aquariums of major importers, are quickly sold to large and medium wholesalers, and then at a somewhat slower pace reach the aquariums of small wholesalers and pet stores, where they often stay for a long time without proper conditions. After all this, the plants do not reach aquarists in the best shape.
The easiest plants to establish are those that grew in similar water and were sold shortly after being removed from their original aquarium. But this does not mean at all that you cannot buy imported plants in pet stores; you just need to treat some of them more attentively. Often plants are sold in latticed plastic pots planted in rockwool. This is often an emersed plant culture. They are grown in a humid environment with a nutrient solution washing over the pots. With plenty of light and nutrients, plants grow very fast. Plants cannot be infected with fish diseases, algae, or snails since they grow above water. Since emersed leaves are much tougher and sturdier, this allows them to be delivered to sellers in excellent condition. Since we plant plants underwater, they still have to adapt to underwater life and replace old leaves with new submersed ones.
The latter often differ significantly from the emersed culture. If an emersed-grown plant is significantly crushed, it is not so important and should not deter you from buying a rare species: anyway, after planting in the aquarium, it will gradually replace old leaves and grow strong shoots. If the plant was in very bad condition, it is better to leave it in the pot until it starts growing.
Never place plants in rockwool into the aquarium — it contains a large amount of nutrients left over from the plant’s production site. This can cause an algae bloom. Before planting, you need to carefully remove the plant from the pot and discard the rockwool. Remove all damaged leaves and darkened roots with sharp scissors. Trim the roots, leaving 1.5–4 centimeters. This will actually help the plant grow new roots faster.
For the proper combination of plant groups, we must know and be able to distinguish large plants, medium-sized, small, and very small aquarium plants. The same applies to leaf types, coloration, and growth rates, which must be considered when arranging plants. Plants that form large leaves and branch well are planted near the back or side walls of the aquarium, framing our display. Single and tall plants are placed in the tank so that their appearance contributes to the decorative composition. The foreground is left mainly for small plants, rocks, and bizarre-looking driftwood. In the middle of the aquarium, we place medium-sized plants. The smallest plants are planted near the front glass of the display.
We will achieve the best result if we group similar plants together and keep these groups separated from one another. Plants should be planted in dense, separate groups (each group should occupy 10–15 cm), with the exception of a few large specimens at focal points designed to draw attention. Dark plants are placed in the background, and light ones closer to the front glass. Plants with long or floating leaves are placed near the side walls. In general, plants are arranged in such a way that shorter ones are closer to the front glass. This provides a better view and creates an illusion of greater aquarium width. Floating plants are the last to be added to the aquarium.
If the aquarist is going to grow particularly light-demanding plants or has to nurse plants that are weakened or need strong lighting or heating, such conditions can be created in the general aquarium without using additional containers. For this purpose, additional shelves are suspended near the side walls or on the back wall, which, when the tank is filled with water, end up at a depth of 10–15 cm. It is best to make them from transparent plexiglass so that they are least noticeable.
How to correlate the quantity and type of plants with the quantity and species of fish?
Plants’ attitude to light intensity. 
Last modified and supplemented on April 19, 2012.
