There are a number of plants that are toxic for betta fish. Some are toxic when ingested, while other release toxic substances into the water. Plants that rot can be toxic for fish since they contaminate the water.
Finally, some plants may cover the surface, obstructing light and making it difficult for a betta to go to the surface to breathe through the labyrinth organ.
There are true aquatic plants that live submerged inside a tank and there are semi-aquatic plants that are emersed, meaning they are partially submerged.
Often non-aquatic plants are used partially submerged and do fine. Beware that fully submerging a non-aquatic plant may survive in the beginning but eventually will die, rot, and change the water chemistry.
Keep in mind that bettas like jumping and having a partially submerged plant will not let you put a much-needed lid on the tank.
Plants to avoid
Peace Lily is not a true aquatic plant. It is commonly used in aquariums and hydroponics because it filters toxins from the water. However, it should not be kept in an aquarium with fish because long term it is toxic to them. The leaves and stems contain calcium oxalate crystals which, when consumed, can cause irritation to the fish’s digestive system.
Pistia stratiotes, also called water lettuce is native to South America or Africa. It is an aquatic plant that can grow up to 12 inches in height. The leaves of the plant are oval-shaped and have a smooth texture. The plant floats on the surface of the water, and it often has small white flowers that bloom on long stalks.
Water lettuce can be toxic to betta fish. Its leaves contain calcium oxalate crystals, which are toxic and can cause illness in betta fish.
In some regions, it is prohibited to plant it because of its invasive nature.
Cicuta, more commonly referred to as water hemlock can grow up to 8 feet tall and have small green or white flowers arranged in an umbrella shape.
Water Hemlock is one of the most poisonous plants in North America. It grows near bodies of water throughout the country.
The plant is poisonous because it contains high levels of cicutoxin. This toxin is most concentrated in the roots. It has a primary toxic effect on the nervous system.
Hygrophila or Hygro Balsamica is a plant that can be found in tropical and subtropical areas. The plant can be grown either as emersed or submerged.
As emerged the plant’s shoots contain high levels of toxins when ingested. If you want to introduce emersed shoots of Hygrophila Balsamica in your aquarium it is highly advised to soak them for a few days.
Bamboo vs Lucky Bamboo
Bamboo is not meant to live emerged in water and will rot.
On the other hand, a similar-looking plant, a water lily called Dracaena Sanderiana or more commonly Lucky Bamboo is perfectly fit for an aquarium. You can grow it submerged or emerged, though emerged seems to benefit the plant better.
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