Water Spangles Care Guide – Planting, Growing, and Propagation

Water spangles (Salvinia minima) is free-floating fern that has gained much popularity in the aquarium hobby due to their very fast growth rate, adaptability, hardiness, and ease of care. In addition, it removes heavy metals (including copper which is a bane in aquarium hobby) very efficiently.

This floater is recommended for everyone in the hobby regardless of their level of experience.

Water spangles are perfect for breeding tanks due to the islets formed by their network of filamentous, submersed leaves which serve as spawning grounds for Anabantids and feeding ground/refuge for a fish fry.

Keep reading for all there is to know about Water spangles; including how to cultivate and care for the species in a freshwater aquarium.

Salvinia minima are widely available for purchase for aquaria and water gardens in the world. Unfortunately, this species is known to be invasive in most of the southern United States, where it is a significant threat to aquatic systems. Therefore, DO NOT throw it down the drain or anything similar.

Quick Notes about Water Spangles

Common Name	Water spangles
Other Names	Common Salvinia, Floating fern
Scientific Name	Salvinia minima
Difficulty	Easy
Lighting	Moderate to high
Optimal pH	6.0 – 8.0
Water hardness	Soft to hard (does not matter)
Optimal Temperature	22 – 26 °C (72– 79°F)
Substrate	Not needed
Growth Rate	Very Fast (Invasive)
Placement in Tank	Floating
Can Be Grown Emersed:	No
Size of the leaves	up to 1.5 cm (0.6 inches)
Fertilizers	Recommended
CO2	Not needed
Propagation	Spore-production or vegetatively through fragmentation or by splitting
Color	Light green

Interesting fact: Salvinia minima exhibits antimicrobial properties against various test pathogens.

Origin of Water Spangles

This is a species of free-floating fern that belongs to Salviniaceae. Salviniaceae is a family of rootless, aquatic ferns that float on the surface of the water. Furthermore, Salvinia is the only genus in this family, and it contains 12 species that are predominantly found in the tropics of America and Africa.

Although native to South America, Salvinia minima were first reported in New York in 1814 with later discoveries of it in southern states.

Water spangles are considered as invasive/noxious species due to their ability to overpopulate, outcompete and inhibit the growth of native water plants in their native habitats.

This floating fern is also capable of clogging irrigation systems and waterways. In addition, it can deplete oxygen levels and dwindle light penetration, thereby degrading the habitats of native species.

Habitat of Water Spangles

Water spangles inhabit the surface of warm, stagnant, or slow-moving freshwater bodies; these include ponds, streams, lakes, and canals.

Moreover, since the fern can tolerate low salinity levels between 4 to 7ppt (1.003 – 1.005 SG)—it also grows in brackish marshes, swamps, and wetlands.

Description of Water Spangles

Water spangles is a small, perennial, free-floating aquatic fern known for its use in freshwater aquaria.

This fern is characterized by the presence of whorls of three leaves: a pair of nearly sessile, round to broad-oval or elliptical leaves while the third is a modified, submerged leaf that is dangling and finely dissected into 5 – 7 segments (about 2.5 – 7 cm or 1 – 3 inches long).

Interesting fact: These root-like projections are not true roots, they are actually modified leaves. 

Water spangles (Salvinia minima) can be differentiated from other species of Salvinia such as Salvinia natans, S. Molesta, S. Auriculata, and S. Rotundifolia by their leaf traits.

Through close observation, the leaf hairs (multiple four-pronged hairs) on the upper surface of Salvinia molesta, S. Natans, S. Rotundifolia are joined at the tip; forming a somewhat “egg-beater” shape. Whereas the leaf hairs of Salvinia minima are spreading and free at the tips.

Water spangles bear numerous leaves with sizes ranging between 1 to 1.5 cm (0.4 – 0.6 inches). These leaves possess specialized cells that facilitate buoyancy.

The leaves are usually green in color with white hairs spread all over the surface. In addition, the prolific, spore-producing ability of this floating fern enables it to form new plants within short periods under favorable conditions.

Tank Requirements and Water Parameters

Salvinia minima is a fast-growing aquatic fern that has high adaptability to various aquatic environments

Tank size:

The plant lies flat on the water surface, and hence it can be kept in tanks of varying sizes and depths. Anyway, because of its fast growth Water spangles should be grown in a 5 gallon (~ 20 L) tank at least.

Water type, Temperature, Hardness, and pH:

Temperature: Water spangles grow in warm waters. It can thrive in temperatures from 20 °C (68 °F) to as high as 30 °C (86 °F), but it’s ideal to keep the water temperature above 22 °C (71 °F) to foster optimal growth and development of shoots.

pH: The plant tolerates a relatively wide pH range, however, pH between 6.0 – 8.0 is considered optimal for this species.

Hardness: Water spangles will thrive in soft to hard water—from 3 to 18 dGH.

Lighting:

Water spangles grow best under bright lighting. In moderate to high lighting conditions, the plant tends to keep a healthy appearance and grow rapidly, whereas in low lighting, the plant’s growth will decline significantly and new shoots may struggle.

To this end, endeavor to supply bright lighting using an artificial lighting source such as a LED light; this should be turned on for a minimum of 10 hours on a daily basis.

Read more about it in my article “Advanced Guide to Planted Tank Lighting”.

Water flow:

This aquatic plant comes from still or slow-moving waters, so it’s appropriate to replicate such conditions in your freshwater tank.

Make sure to provide still or low water currents for Water spangles or they will not survive in the long run.

Co2 and fertilization:

The plant does not require additional CO2 dosing as it gets enough from the air, therefore, CO2 injection is optional.

With regard to fertilization, Water spangles appreciate the addition of liquid plant fertilizers in the water column since it absorbs a great deal of the required nutrients from the water to bolster its growth.

Important: If you keep shrimp in the tank with Water spangles, I would highly recommend reading my articles:
CO2 in a Planted Tank Guide
CO2 in a Shrimp Tank
How Copper Affects Dwarf Shrimp
Shrimp Safe Plant Fertilizers
The point is that a high level of CO2 and Copper (most fertilizers contain copper) is extremely dangerous to the shrimp.

Care and Maintenance of Water Spangles

Water spangles are relatively easy to care for as it is beginner plant, however, much effort should be channeled towards preventing the plant from overshadowing the entire water surface.

This plant is capable of growing fast and forming new shoots in record time. Under optimal conditions, it can easily double and triple in size in 7 – 10 days.

Therefore, you should always keep its growth in check through constant pruning of the dense foliage.

Make sure to prune the foliage constantly, or else the shoots will overcrowd the water surface; thereby blocking light from reaching the plants at the bottom of your tank. Do well to utilize this opportunity to get rid of sick or damaged leaves and dispose of it together with the clipped foliage in plastic bags.

Another necessary activity is the application of liquid fertilizers—rich in essential nutrients to replenish nutrients required by the plant for optimal growth. Lack of essential nutrients results in a deficiency and this is often indicated by signs such as discoloration of the leaves and poor growth.

Water flow is crucial to the health of Water spangles. So, provide low water currents as the plant thrives in slow-moving waters in the wild.

Lastly, maintain good water quality in your aquarium by siphoning about 25% of the tank water bi-weekly and replacing it with clean, dechlorinated freshwater.

Planting and Propagation of Water Spangles

To cultivate Water spangles in your aquarium; split the plant into several portions and disinfect them to get rid of snails and other unwanted pests/parasites.

After that, spread the portions uniformly on the water surface.

Keep in mind that covering the whole surface of your aquarium with Water spangles is not needed since they will grow and form numerous, new shoots.

You may form a ring using airline tubing or any suitable equipment in order to confine the plants to a particular area in your tank. By so doing, light will easily penetrate into the water column and there won’t be much shading.

Water spangles reproduce mainly through spore-production in their natural environment. However, in the aquarium, the plant propagates vegetatively through fragmentation i.e. the continuous branching and breaking away of lateral and terminal shoots.

Moreover, one can split the horizontal branches formed by the existing plants to create new, independent plants.

Problems Associated With Water Spangles

Overgrowth: Water spangles are capable of overrunning the tank due to their fast growth rate (luckily not as fast as duckweed).

Thus, excess or overgrown foliage should be pruned frequently, or else it will overcrowd the water surface, create shades and block light from getting to live plants at the lower levels of your tank.

Discoloration: This is a sign of poor health—usually prompted by a lack of essential nutrients in the water column or light.

To forestall this problem, make sure to apply plant fertilizers and iron supplements regularly in the right doses to replenish depleted nutrients. The availability of nutrient-rich water will reward your plants with an even, lush green coloration and robust growth.

If that fails you could try increasing the duration of your lighting.

You can also read “How to Spot Nutrient Deficiencies in Aquatic Plants”.

The plant becomes smaller: Salvinia minima do not like flow, this species prefers still water. Therefore, if the shape of the new plants is smaller than the original plants, it can be the reason.

You can make a protected circular area with an air pipe that can surround the plants. It will reduce the impact of the flow. 

Oxygen depletion: Since this species has slow-moving water/ low water currents as a key requirement; surface agitation (which promotes gaseous exchange) decreases and this impacts the rate at which oxygen dissolves in the aquarium water.

So, it is advisable to keep a small number of Water spangles in your tank. The aim is to prevent a situation where the plant forms a thick layer on the entire water surface and depletes dissolved oxygen levels to the detriment of your aquarium fauna.

Benefits of Water Spangles

Aesthetics: Salvinia minima covers the top layer of the aquarium and adorns it beautifully.

Removal of excess nutrients: Salvinia minima has heavy metal absorption properties. It is helpful in absorbing harmful chemicals that are emitted from fish waste, decayed plant matter, and tap water such as nitrates, CO2, ammonia, and phosphates.

According to the experiments, Water spangles reduced ammonia (NH3) by 89.9% in the untreated wastewater after 8 days of treatment. It also showed good results at removing copper from water.

Filtration: It is also extremely efficient at organic pollutant removal.

Algae control: Salvinia minima helps to effectively reduce the growth of algae. It sucks all the nutrients up real fast. Basically, it outcompetes algae, therefore, diminishes the number of algae cells in the water column.

Shelter / Cover: Some fish species and the frier will use this plant as shelter. In addition, other aquatic species; both fauna and flora dwelling in the aquarium, will appreciate the shade provided by Salvinia minima. Without any doubt, shrimp will love Duckweed.

Foraging place: Acts as a buffet of biofilm, which is an ideal first food for newly hatched fry and shrimplets. Shrimp love to nibble on the roots of Salvinia minima.

Light penetration: I have mentioned it as a problem before but it can also be a good way to filter lights if you have plants that do not need it (for example Java Fern, Amazon Sword, Marimo Moss Ball, Anubias, etc.).

For more information, read the article “Top 10 Low Light Aquarium Plants. Pros and Cons”.

Prevents fish jumping: Once Salvinia minima cover the surface, it will keep fish from jumping, when you do not have a lid.

Easy to remove and control: They grow in chains, so, you can clear the tank within minutes.

Water Spangles and Compatible Tankmates

Water spangles are compatible with aquatic species that can thrive in a shaded aquarium, as well as species of fish that build bubble nests.

Fish:

The modified, filamentous leaves of Water spangles create a favorable medium for egg spawning. And Anabantids such as Bettas and Guoramis will appreciate the comfortable spot formed by the root-like leaves of Water spangles.

Apart from these, other freshwater fish species like Neon Tetras, Ember Tetras, Platies, Guppies, Corydoras Catfish, Zebra Danio, Celestial Pearl Danios, and Cherry Barbs, Endlers, Mollies, Otocinclus Catfish, Pygmy Cory Catfish, can be kept with Water spangles.

Dwarf Shrimp and Snails:

That’s not all, invertebrates such as dwarf shrimp, freshwater snails as well as freshwater crabs, and crayfish species are equally compatible.

• Dwarf Shrimp (All varieties of Neocaridina (Red Cherry Shrimp, Blue Velvet Shrimp, Snowball shrimp, Black Rose, Orange Sakura, Green Jade, Rili Shrimp, etc) or Caridina species (for example, Crystal Red Shrimp, Caridina cf. babaulti, Blue Tiger Shrimp, etc.), Amano shrimp, Ghost shrimp, Bamboo shrimp, Vampire shrimp, ). Basically, you can keep any shrimp species with it. They will love it!
• Snails (for example, Japanese trapdoor snails, Ramshorn snails, Nerite snails, Malaysian Trumpet snails, Black Devil Snails, Asolene spixi, Rabbit Snails, etc.).

Note: Crayfish and crabs. It can be very hard to keep these animals in planted tanks. Most species will try to uproot and eat everything until they turn your beautiful tank into a wasteland. That is why floating plants will be a good choice for them. They simply won’t be able to get them, so you should have a problem.

Avoid or Be Careful:

Nonetheless, try as much as possible to avoid large, aggressive fish species like Scats, Oscars, Jack Dempsey, Koi fish, Buenos Aires Tetras, and Silver dollars that will chew the fronds of your Water spangles.

You can also read my article “Fish Causing Problems in Planted Tanks”.

Buying Water Spangles

Water spangles is a popular and widely available species; thus, it can be purchased at local fish stores and online through reputable vendors.

 The price may vary among vendors, though on average, a small cup goes for $5.

What you should look out for while shopping for this floating fern is: vibrant green coloration and healthy shoots without rips, holes, algae, decay, and discoloration. Getting healthy Water spangles should be a priority!

Quarantine Water Spangles

Unless you are completely sure that the plant is safe, for example, it was grown in sterile/laboratory conditions (in vitro) and in vitro pot is not damaged or opened, do not forget to quarantine and disinfect Salvinia minima to avoid the risk of contamination.

• The plant can have parasites, and hitchhikers like pest snails, or even predators (dragonfly, damsefly nymphs, etc.).
• It could also be treated with chemicals (pesticide) to remove parasites, snails, etc. However, these chemicals are extremely poisonous to fish, shrimp, and other invertebrates.

To find out more, read my articles:  

How to Remove Snails from a Shrimp Tank.
How to Quarantine and Disinfect Aquarium Plants.
Pesticides in Shrimp Tanks. Plants Quarantine.

In Conclusion

Water spangles (Salvinia minima) is a popular aquarium plant and one of the best floating plants for freshwater aquaria.

The species is quite undemanding, and it can form thick mats on the surface of your tank water in no record time—with or without CO2 and fertilizers!

If you are searching for an easy, hardy, and fast-growing floater for your aquarium, look no further, because Water spangles ticks all the boxes.

Related articles:

Top 7 Floating Plants for Beginners
Aquarium Floating Plants. Pros and Cons

Water spangles (Salvinia minina)  – check out the price on Amazon