|Origin||:||South and Central America|
|Growth Rate||:||Medium to Fast|
|Light Demand||:||Medium to High|
Limnobium laevigatum that is also known as “Amazon Frogbit”, “West Indian Spongeplant”, “South American Spongeplant” or “Smooth frogbit” is an aquatic plant species belonging to the Hydrocharitacea family. The natural habitat of this plant is Central and South America, but later it has been introduced in California, United States. This plant, first discovered in the early 1800s, takes its name from the Greek word ‘limnobios’ which means dwelling in a lake. Rivers with slow-flowing water streams, ponds, or wetlands are the natural environments of Limnobium laevigatum.
A mature Limnobium Laevigatum can grow up to 50 cm. The leaves of this plant are smooth, wide, green, bright, and they can reach up to 5-15 cm wide. This plant also has capsule-shaped 4-13 mm long and 2-5 mm in diameter fruits that can contain up to 100 seeds. 1 mm tall hairy and elliptical seeds and small white flowers are specific to Limnobium laevigatum. It has very long root structures compared to other floating plants. These roots can serve as shelter to small fish and fish fry as well as providing starter food for the fish fry. The microorganisms living on the roots of this plant are a good source of food for the tiny fry in their first days of life.
The ideal water pH balance for this plant is between 6,0-7,5 and the optimum water hardness is between 1-12 dGH. It can tolerate both soft and hard water. The ideal tank size is 10 liters for the plant to grow healthy and it is not suitable to grow in nano tanks. It is necessary to keep the water temperature between 18-26°C for proper plant growth. Even if it can tolerate cooler water temperatures, low temperatures will reduce the growth rate of the plant and cause the leaf size to remain small.
This plant needs light due to its nature. Therefore, medium or high-intensity lighting is necessary for proper growth. For the best results, using full-spectrum lights such as T5, T8 bulbs, LED lights are suitable with a lighting period of 10 to 12 hours per day. Carbon dioxide addition is not necessary for growth, but it increases growth rates. Since it is a floating plant, substrate selection has no significant effect on plant growth. The plant roots can capture even small floating organic particles and use them as nutrients but, for continuous and healthy development, it requires nutrient addition to the aquarium water because it quickly consumes the nutrients existing in the water.
Limnobium laevigatum is a flowering and seedy plant that can propagate sexually in its natural life, but this method is not suitable for the aquarium. For the propagation of this plant, the most appropriate technique is stem fragmentation. In this process, the parts separated from the mature plant as stolons grow independently and turn into new plants.
One of the major problems encountered in the care of the plant is damage to the roots. Very long and delicate roots can break due to high water currents or those caused by other aquarium inhabitants. For this reason, it is necessary to prefer constant or slow-flow water in the aquarium. Fish such as tetra, betta, and gouramis or snails like pond snails, nerite snails, or mystery snails can live in harmony with this plant. Another problem is that if the plant does not get enough light, its color will turn from green to brown. If such a problem is encountered, the lighting method and duration must be adjusted accordingly. On the other hand, Limnobium laevigatum can also harm other inhabitants in the aquarium, especially other plants. Rapid growth rate and broad leaves can prevent light from reaching the aquarium’s lower layers, and that may cause other plants to die or lose condition. Thus, in case there are other submerged living plants live in the same aquarium, regular and partial removal of Limnobium laevigatum is mandatory to let other plants grow healthy.
Besides its beautiful and lively appearance, Limnobium laevigatum also provides various benefits to aquarium life such as algae control, a shelter for fish and snails, and filtration of water by removal of excessive nutrients. For these reasons and easy care, it is a preferred and loved plant for aquarists of all levels.