Basic compatibility of aquarium plants

It appears that the vast variety of aquarium flora allows you to use your imagination when selecting plants for the design of your fish tank. In fact, different species’ “preferences” in terms of lighting, water temperature and acidity, carbon dioxide content, micro-macro elements must all be taken into account. Otherwise, the outcome will not be what you expect. After all, some aquatic plant species have such contrasting environmental requirements that creating a single comfortable environment for them is either impossible or extremely difficult.

Compatibility of aquarium plants

Some people believe that certain plant species cannot be grown together in the same aquarium because they are incompatible. The examples given in these cases are typically unconvincing, especially when considering the optimal lighting and hydrochemical parameters required for plants to function normally. In fact, rather than some mysterious substances released by some plants suppressing the growth of others, it is differences in the requirements for certain natural circumstances (their roots are in the peculiarities of natural habitats) that usually determine the possibility of joint care of plants in the aquarium.

Plants, as you may know, are living organisms with diverse diets. This means that you’ll need to create normal photosynthesis conditions, such as lighting and carbon dioxide(CO2), as well as a complete set of chemical elements, such as nitrogen, phosphorus, potassium, and a number of elements that we’re all familiar with from school. All chemical components in the aquarium’s water must be present in a form that the plants can easily digest, i.e. in the form of solutions. At the same time, it’s critical to understand that the lack of or restriction of at least one of these factors or their components is a limiting condition for the entire plant food system that can’t be overcome by increasing the concentration of other elements. So, if there is a deficiency of iron in the aquarium’s water, the course of plant development will be determined by this circumstance, and an abundance of other elements will not compensate for this deficiency. The same is true for lighting, because the length of daylight, the intensity of radiation, and the spectral composition of light sources all have an impact on plant life.

In a closed aquarium system, there is usually no shortage of nitrogen or phosphorus, but rather an excess, resulting in water “cloudiness” Furthermore, excess nitrogen and phosphorus depress aquatic plants, as if poisoning them, in the same way, that it poisons fish. During regular water changes, other macro-and microelements in varying amounts enter the fish tank (iron comes e.g. from the water pipes made of steel or metal frame of an aquarium). In comparison to natural water bodies, however, there is usually a carbon dioxide shortage. This is particularly noticeable in aquariums with good ventilation, where carbon dioxide is released into the atmosphere via the surface layer. As a result, it is desirable to introduce carbon dioxide into aquariums with plants in some way.

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Hardness and acidity

A shift in the acid-base balance in the direction of alkalinization and a high concentration of calcium salts are ideal for some aquatic plants. Other aquarium flora species, on the other hand, thrive in soft water and low alkaline content.

As a result, getting along with the Potamogeton and the floating riccia in an aquarium will be difficult.

The Potamogeton’s bright emerald leaves stop growing and lose their color due to calcium, magnesium, and potassium deficiency, the plant dies and may even die. Riccia, at the same time, doesn’t feel as good in high PH water.

As a result, even though their design characteristics are perfect for each other, it is best not to put these two plants in the same fish tank.

Most aquarium plants, fortunately, thrive in neutral acidity (pH 7). As a result, the level of acidity and hardness of the water plays a small role in limiting the number of “neighbors” in the plant aquarium.

Chemicals. Micro and macro-elements

Aquarium vegetation necessitates a long list of macro-and microelements. Nitrogen, phosphorus, carbon dioxide, sulfur, iron, boron, copper, molybdenum, zinc, sodium, and manganese are among the elements on this list. For different plant species, the optimal concentration of each of the above chemicals and compounds can vary significantly.

Cryptocorynes, for example, require a sufficient amount of bivalent iron to fully develop and achieve their stunning brown-red-violet color. At the same time, too much of it can harm a seemingly unpretentious plant like Vallisneria.
Vallisneria is a light, loving plant that isn’t fond of iron.

The above-mentioned Vallisneria and for instance, Hydrilla can both be poisoned by high iron content.

To be fair, it should be noted that the Fe2+ concentration can be adjusted to the point where Cryptocoryne and Wallisneria,  Potamogeton, and Hydrilla are unaffected. Chemical mixtures with Ferrum and other ferrous fertilizers for aquarium plants “will assist you.”

However, with the amount of carbon dioxide in the water, you must concentrate on the “most voracious appetite.” The cryptocorynes are once again the dominant species in the above-mentioned plants’ community. At neutral acidity, the concentration of carbon dioxide in an aquarium with Cryptocorynes should be at least 15 mg/liter.

Basic compatibility of aquarium plants


In an aquarium, it can also be difficult to “combine natives” from southern and northern latitudes.

“Southerner” plant Limnophila will not cause any problems  If the water temperature is kept between 24-28°C.

However, limnophila cannot be kept in the same basin as the moss fontinalis. At 14-20°C, the fontinalis moss thrives and develops, preferring crystal clear water with a slightly acidic pH. Although some fishkeepers can keep fontinalis in good condition at 24°C, it does not tolerate long-term immersion in such an aquarium temperature.


Plants love light, and it’s possible that this is the only parameter in which all members of the aquarium flora are completely compatible. Simultaneously, properly adjusting the lighting of various zones in the fish tank allows combining species that require a large amount of carbon dioxide with plants that can survive on a small amount of carbon dioxide and do not react well to excess carbon dioxide.

Active CO2 consumers should be planted in well-lit areas if there is only one light source. Plants that do not consume large amounts of carbon dioxide should be shaded away from lamps so that carbon dioxide absorption is slowed and excess carbon dioxide does not harm them.

You could also take a different approach and illuminate the area around cryptocorynes or other species that require high carbon dioxide concentrations. Such complex lighting will create an interesting visual effect and become a full-fledged design element, in addition to providing comfort for the aquarium flora with different CO2 metabolism.

We come to some conclusions.

Collecting various aquarium plants in a single fish tank is a difficult but doable task. Among the vast array of species, you will undoubtedly come across those that:

  • They will match your aesthetic features;
  • They will be able to “get along” with each other as well as the aquarium’s population – fish, shellfish, and so on.

Potamogeton  and Hydrilla, for example, will make excellent “neighbors.” Plants on both sides:

  • They don’t like being oversaturated with iron
  • They look great and thrive in hard, warm water.

As a result, if you approach the situation correctly, you will be able to create a full-fledged healthy ecosystem as well as beautiful underwater landscapes.

Seek the help of professionals if you don’t have the time or desire to learn about the intricacies of aquarium flora selection and subsequent care. We can add live plants to your artificial pond, show you how to properly care for the “underwater garden,”.

Basic compatibility of aquarium plants