How To Get Rid of Duckweed in Aquarium

how-to-get-rid-of-duckweed-in-aquarium

There is a wide variety of aquatic flora and fauna to include in an aquarium. However, there are sometimes unwanted guests that come to settle in the environment like duckweed. We provide you with information about duckweed, which can be both beneficial and harmful to the population of your fish tank.

Duckweed: what is it?

Duckweeds are aquatic plants that are found mainly in fresh water, in lakes, ponds or puddles. They appear on the surface taking on the appearance of a grass. This vegetal carpet floats and often deceives the vigilance of walkers or animals that rush in when they are not careful about where they are going.

If visually, these plant formations are all a bit similar, there are several types. These differ by their size, but also by their form when one looks at them more closely.

The Lemna minor

It is the most known and the most common in the water bodies and it is nicknamed the small duckweed. The Lemna is between 1 mm and 3 mm in diameter. This duckweed resists little to the frost and to the winter, but it returns with the return of the beautiful days. It has as quality, a good absorption of harmful substances in water as nitrogen or phosphorus.

The Lemna gibba or humpback

A little larger, it advances a size between 2 mm to 5 mm. It presents an invisible bloom, but with rounded and a little bumpy fronds. It is usually found alone. This variant does not support the cohabitation with the other lenticules.

Wolffia Arrhiza

It is easily recognized because it is the only one of its species without roots. Its observation requires the use of a microscope because it is not perceptible to the naked eye. It is less than one millimeter thick.

Lemna trisulca or Trilobate

It measures between 5 to 15 mm and includes three veins on its thallus. It does not resist to the high temperatures and is en endagered specie.

Lemna polyrhiza or with numerous root

As its name indicates it, it can comprise several appendices and reach about fifteen. At the time of the bloom, those develop until having 1 cm length sometimes.

Lemna minuscula or Tiny

It comes to us from the American continent and its dimensions do not exceed those of Lemna minor, i.e. less than 1 mm.

How do these plants reproduce and under what conditions?

These aquatic plant formations are distinguished above all by their relatively rapid growth. They float thanks to the presence of a frond often filled with air. The absence of stems and leaves allows them to be found on the surface or for some, below the water level. These plants may or may not have roots, depending on the duckweed species.

Duckweeds use asexual reproduction to perpetuate themselves. With plant propagation, they reach a considerable number in no time in a suitable environment. For example, a mother duckweed duplicates itself in two. After a few days, the latter will dissociate from the first and produce two specimens in turn and so on. The process can cover your aquarium at high speed if you are not careful.

To multiply, however, these aquatic flora need an ecosystem with specific conditions. They thrive in an environment where the temperature is generally between 6°C and 33°C. They also thrive if you offer them water with a high nitrate content in your fish tank. It is also important to remember that these green plants require light to perform their photosynthesis.

What are its advantages and disadvantages?

Despite what we may think about these lenticels, their presence in your aquarium can have many advantages. Since they feed mainly on nitrate to develop, they help in the purification of the water in the tank. They will then play a role in bioremediation as they absorb excess nitrogen or phosphate. The high concentration of the latter could alter the health of your animals. Moreover, they are fond of these duckweeds, especially carp and goldfish.

This vegetal mat also plays a role in water conservation by reducing evaporation and can serve as a refuge for fry to take shelter. In some cases, it prevents the formation of certain photo-autotrophic algae.

However, duckweed can also inhibit the growth of a submerged aquarium plant. In addition, duckweed is particularly invasive and can quickly cover your container if left to its own devices.

What techniques should be used to eliminate them?

The first advice of specialists remains the prohibition of chemical products. These can disturb the balance of the aquatic environment and then alter the development of other inhabitants of this ecosystem.

One of the alternatives to undertake remains the manual work. Using a net with fine mesh or a similar tool, you can apply yourself by removing them with your hands. Note however that the operation can become quite tedious especially if you have a large quantity of lenticules to remove.

If you are not a fan of manual interventions, you can always get an air pump to push them to the edges and thus facilitate their extraction. This machine will also help the oxygenation of the environment.

Another possibility is to add one or more heliophytic plants, i.e. plants with large roots that can be embedded in the substrate, but with stems and flowers that emerge from the water.

These aquatic plants are known to be nutrient absorbers and will help regulate nitrogen and phosphorus levels, which are the main factors in duckweed development.