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Best Floating Aquarium Plants
Floating aquarium plants are aquatic plants that float on the surface of water instead of being rooted in the substrate. These plants have specialized structures, such as air-filled tissues or buoyant leaves, that allow them to stay afloat.
Types of Floating Plants
Floating plants are categorized into two groups.
1. Floating-leaved
These are aquatic plants with leaves floating on the surface of the water while their roots or stems touch the substrate in the aquarium or dangle in the water. Some common examples are Amazon Frogbit (Limnobium laevigatum), Water Lilies (Nymphaea spp.), and Water Poppy (Hydrocleys nymphoides).
2. Free-floating
Free-floating aquatic plants don’t anchor their roots in the substrate or suspend them in a water body; rather, they float freely on the water surface, absorbing nutrients directly from the water. Some common examples are duckweed (Lemna minor), Water Lettuce (Pistia stratiotes), and Salvinia (Salvinia natans).
Benefits of Floating Plants
i. Natural Filtration
Floating plants act as natural filters, absorbing nitrates, phosphates, and other waste from the aquarium. They rely on nutrients present in the water column for survival rather than within the substrate.
ii. Algae Prevention
One of the major benefits of floaters is their ability to outcompete algae, thus preventing its excess growth. Unlike stem plants, which take some time to adjust and develop roots to combat algae, floating plants are exceptionally unique. They start growing and utilizing excess nutrients right from the start. This feature makes them an excellent choice for new setups where the tanks have yet to stabilize.
iii. Protection
Floating plants are a great source of security and protection for fish that are not very outgoing and prefer to hide in hiding spots, such as shrimp and guppies. They also offer a sense of security for timid bettas, who feel more comfortable under their cover.
iv. Shade and Shelter
Floating plants are ideal for aquariums, with plants that thrive in low to moderate light. Examples include Anubias. These plants help create shade and can reduce light to the desired levels when positioned correctly.
Floating plants are highly recommended for aquatic creatures such as Corydoras, Apistos, and many Tetras, which you can keep in your aquarium as betta fish mates. These plants help these animals feel safe and secure in shaded environments.
v. Aesthetics
Floating plants can add a natural and pleasing aesthetic to your aquarium, enhancing its overall appearance.
Disadvantages of Floating Plants
i. Rapid Growth
Some floating plants grow vigorously, taking up the entire tank, which can lead to major maintenance issues and less swimming space for the aquarium inhabitants.
ii. Light Limitation
While floating plants provide beneficial shade, they can also significantly reduce the amount of light reaching other plants underneath that require high light levels.
However, there is a solution to this problem. To prevent the blockage of light, keep floaters in a larger corner of the tank using a corral, cull excess plants as they multiply, and sell them to nearby fish stores.
I have been doing this for a long time by making circles and half circles using the corral. You can also do the same by using airline tubing and shaping it into rings; however, the issue with the airline is that it does not stay flat on the surface. To address this, heat the plastic tubing by dipping it in warm water and then allow it to cool down in order to lay flat.
iii. Nutrient Demand
In most cases, floaters are best at consuming algae and excess nutrients. However, because they grow quickly, floating plants require a lot of nutrients, and sometimes, your aquarium may not have enough. This can cause other stem plants to suffer from nutrient deficiency. To fix this, add extra fertilizers or regularly remove excess floating plants from the tank surface.
iv. Blocking Surface Access
Most stem plants require gas exchange between the water and the atmosphere. If there are plenty of floaters in your tank, these plants may be deprived of gas exchange, potentially causing oxygen depletion. This can make it impossible for fish and underwater plants to survive.
Top 6 Best Floating Aquarium Plants
There are many floating plants you can grow in an aquarium, but to simplify your choice and avoid confusion, we’ve highlighted the top 6 best floating aquarium plants. These plants are suitable for almost any fish tank.
1. Amazon Frogbit (Limnobium laevigatum)
Amazon Frogbit is a floating-leaved aquarium plant, with lily-shaped leaves. Its roots grow really long, creating a stunning appearance. Due to its large leaves, it’s known for providing ample shade and creating excellent hiding spots for fish fry. It grows rapidly and is ideal for new setups, as it helps reduce algae growth. To support its role as an algae remover, enrich it with nutrients and provide sufficient light for it to reach the other plants underneath.
Regarding requirements, this plant is low-maintenance and does not need CO2, making it the best option for beginners. Another reason that compels beginners to go with this plant is its water-resistant surface. Its leaves do not rot or melt when submerged underwater. Shrimp and snails are well-suited to this plant.
It’s not ideal for smaller tanks, especially in shallower ones with little vertical space, due to its extensive root growth. To prevent its deep roots from causing issues in your tank, it is better to trim its roots regularly if they cause obstruction for other things in your tanks.
This plant can be grown in an aquarium with a lid, but there should be a sufficient distance of one-quarter to half an inch between the water line and the lid.
Frogbit and betta fish are very compatible since neither requires water surface flow. The plant can wilt with excessive surface ripples, which suits the betta’s preference for calm water.
2. Water Spangles (Salvinia minima)
Water Spangles, commonly known as Salvinia, is a unique free-floating fern with small oval leaves covered in tiny hairs. It grows on the surface of still or slow-moving water bodies. It’s also well-known for its natural filtration properties, which help prevent algae growth. It’s quite a hardy and durable plant that can thrive in a wide PH range and light intensities. Because of its small leaves, Salvinia is not problematic under the lid. Since it’s a free-floating aquatic plant, its roots stay shallow if well fertilized and don’t hinder the view and cause obstruction like other floaters.
The only drawback I see is that when Salvinia grows too dense, it gets caught in other plants, making it very challenging to remove from the tank. Also, it can easily get trapped underwater if there is a strong water current or surface agitation. It’s important to prevent a lot of water droplets from accumulating on the surface of the leaves because if they stay underwater, they may rot.
Similar to Frogbit, Salvinia thrives without the need for water surface flow, so it can be a good addition to betta tanks.
3. Dwarf Water Lettuce (Pistia Stratiotes)
Dwarf water lettuce is a free-floating water fern with rosettes of light green, velvety leaves that grow extremely fast. It has a delicate root system that can easily be broken and trimmed if you want to remove excess of it since it can spread with short roots. This plant requires ventilation or air flow to thrive, so it is best suited for stagnant water or ponds, but you can grow it in an aquarium with a suitable arrangement for the airflow.
Additionally, water lettuce absorbs a lot of nutrients, especially nitrogen. If the tank experiences a nitrogen deficiency, the leaves of the water lettuce will melt to release nitrogen, which other parts of the plant can then reuse. This plant can take up a lot of space in the tank, making it difficult for your fish to find swimming areas, particularly in small tanks. However, larger tanks can easily handle this issue.
Since water lettuce grows very quickly and can reach the lid, potentially blocking light to other plants below, it’s important to scoop out two or three handfuls every week. Its leaves can rot if submerged or exposed to a spray bar or waterfall, so keep the top dry and prevent water from your filter from pouring onto the leaves surface.
For all these reasons, I categorize this plant to be of medium difficulty, and beginners should carefully consider and understand its requirements before choosing it.
Because of its long, soft, bushy roots, water lettuce provides a perfect snuggling spot for your betta fish.
4. Red Root Floater (Phyllanthus fluitans)
Red root floaters are South American free-floating ferns known for their vibrant red roots and reddish-green leaves. Floaters typically have green leaves but can turn red when exposed to very high-intensity light. When exposed to high light, make sure the floaters cover the whole tank surface so that they do not result in algae growth.
For light monitoring, increase the light level gradually—first by 5% every three days. If you notice algae growth, reduce the light by 5% until the algae stops growing. Then, increase it by 5% every other week until you see the desired look of the ferns.
For beginners, taking care of red root floaters demands more effort and attention. They are sensitive to surface agitation and can be stuck underwater and melted by too much agitation. Additionally, they are finicky and consume too many nutrients. You may need to dose them with fertilizer to keep them looking healthy and vibrant. I also add iron weekly alongside other fertilizers, which significantly enhances the roots’ growth, giving them a deep red color.
5. Duckweed (Lemna minor)
Duckweed is a small and fast-growing aquarium plant consisting of tiny, free-floating leaves that form a dense mat-like cover on the water’s surface. While it provides an aesthetic cover, allowing it to cover the surface completely can shade the entire tank and have a negative impact on gaseous exchange and other important parameters, such as feeding the tank inhabitants. It’s supermassive, can occupy the whole tank, and overwhelm the filters and other accessories. Only the giant form of duckweed is manageable and easier to maintain as compared to its standard species.
Some fish keepers have good experience with thriving bettas in the tank when duckweed is present, but in this case, they have to use the corral to allow their bettas to breathe from the surface. Duckweed is problematic in many setups, so I wouldn’t recommend it for beginners. Once you grow it in your aquarium, it’s very difficult to get rid of it. I use it solely for a specific reason.
6. Hornwort (Ceratophyllum demersum)
Hornwort is a free-floating known for being one of the easiest to grow. Here are some reasons to have this plant in your aquarium:
- It can thrive without CO2.
- It needs minimal nutrients and light, thriving even with the built-in LED lights in most tanks.
- Hornwort doesn’t produce foliage, making it useful for filling blank spots in your aquarium.
- It is highly effective in removing algae from your aquarium as it releases an algaecide that chokes out algae.
- It absorbs nitrates, a feat no other plant can achieve like hornwort.
Most fish love this plant and breed prolifically in it. Your shrimp would adjust well to this plant. Many carp species and larger fish, in general, enjoy eating it.
Hornwort can be finicky to maintain in your aquarium. You have to use liquid fertilizer when having hornwort in your aquarium, as it mostly sucks off useful nutrients along with algae. Some fish keepers may find the free-floating needle-like roots unattractive, as they resemble a Christmas tree. To address this, it’s best to regularly trim the roots and avoid burying them under the substrate as they can rot if left in this condition.
Conclusion
Floating plants are a superb addition to almost every fish aquarium. They bring something unique to your tank that stem plants cannot offer. These floaters are ideal for achieving a balance between nutrients, light, and submerged plant growth because they consume excess of either. Additionally, these plants are very easy to grow, making them a must-have for every beginner.
Read our article on the betta fish plants for your aquarium, which covers only stem plants.