Why Amazon Frogbit Roots Could Be the Best Thing for Your Aquarium!

Amazon Frogbit (Limnobium laevigatum) is a popular floating aquatic plant known for its lush green leaves and downward-facing roots. Native to South America, this plant has become a mainstay in aquarium hobbyists due to its fast growth, resilience, and ability to absorb excess nutrients in the water column.

While the leaves provide beneficial shade for fish, the roots are the show’s true star. Ranging from a few inches to over two feet long, the roots provide shelter and enhance the natural environment. Proper care is required to maintain optimal root growth.

What is Amazon Frogbit?

Amazon Frogbit is a floating perennial plant belonging to the family Hydrocharitaceae. It is native to still and slow-moving freshwater rivers, streams, ponds and lakes in parts of South America including Brazil, Paraguay, Uruguay and Argentina.

The plant has round to oval shaped leaves measuring 1-2 inches wide that float flat on the water’s surface. The leaves are attached to spongy, bulbous stems that float just below the surface. Roots emerge from the underside of the bulbous stem and dangle freely in the water column.

In the wild, Amazon Frogbit serves as a natural filter by absorbing excess nutrients like ammonia, nitrates, and phosphates from the water. The extensive root system provides shelter and shade for fish.

Amazon Frogbit is a popular choice for aquarium hobbyists because it grows quickly, is easy to care for, and adds an aesthetically pleasing natural element to the aquascape. The shade created improves water quality by blocking light and inhibiting algae growth.

Amazon Frogbit Care

Caring for Amazon Frogbit is relatively simple, but there are a few key factors to get right to achieve optimal growth:

Water Parameters: Amazon Frogbit thrives in slightly acidic water with a pH between 6.0-7.5 and a temperature of 70-82°F. The water should be relatively soft with a hardness less than 15dGH.

Lighting: Moderate lighting between 0.5-1.5 watts per gallon is ideal. Low to medium indirect light is best. Avoid intense direct light as it can burn the leaves.

Nutrients: Amazon Frogbit is not a heavy root feeder but some key nutrients are required. A liquid fertilizer provides trace amounts of iron, nitrogen, potassium and phosphorus. CO2 injection can also accelerate growth.

Water Movement: Still to slow moving water is preferred. The delicate roots can become damaged in strong currents. Gentle surface agitation is fine. Avoid filters with an aggressive outflow.

Tank Size: A 10 gallon tank is usually sufficient, but larger is always better. Each plant needs at least 1-2 square inches of surface space to float and grow properly.

Amazon Frogbit will thrive and produce an extensive root system with the right conditions. Let’s take a closer look at why these roots are so important.

The Significance of Amazon Frogbit Roots

The roots of Amazon Frogbit serve several important biological and aesthetic functions:

Shelter & Security

The fine, downward facing roots provide an intricate web that small fish and fry can use to hide from predators and aggressive tank mates. Shy species like tetra and rasbora will appreciate the security of the submerged jungle.

Surface Area for Beneficial Bacteria

The sheer amount of surface area created by the root mass makes an ideal home for populations of beneficial bacteria. These microorganisms help break down waste and prevent the accumulation of harmful chemicals.

Oxygenation & Gas Exchange

As an aquatic plant, Amazon Frogbit generates oxygen through photosynthesis. The long roots facilitate the diffusion and exchange of oxygen and other gasses between the water and the air.

Nutrient Absorption

The plant roots can draw in and absorb ammonia, nitrates, phosphates and other excess nutrients from the water that would otherwise lead to algae growth. This helps keep the water clean.

Natural Appeal

The extensive root system looks amazing! It adds movement, depth and a sense of nature to the aquarium. The roots can grow to dramatic lengths over 12 inches.

Surface Coverage

The floating leaves spread across the surface helping block light and prevent surface algae growth. The roots fill in space beneath to create full coverage.

Maintaining healthy roots is critical for getting all these benefits in your aquarium. Next we’ll go over how to control the length.

Managing Amazon Frogbit Root Length

Amazon Frogbit roots can reach up to 24 inches long in the wild. In an aquarium, lengths between 4 to 12 inches are more common. If the roots become unruly, trimming them is easy:

Why Trim?

  • Roots block light needed for other plants
  • Entangle with equipment like the heater
  • Collect debris and start to rot
  • Take up too much space for fish to swim

How Often?

  • Trim as needed, usually every 2-4 weeks
  • Faster growing tanks may need weekly trimming
  • Slow growing tanks can go 4-6 weeks

Trimming Procedure:

  1. Remove Frogbit portion from tank
  2. Use sterilized scissors or razor blade
  3. Trim roots to desired length (2-6 inches)
  4. Discard excess roots
  5. Return Frogbit to tank
  6. Repeat process for remaining plants

Trimmed roots will regenerate new growth within 1-2 weeks. Spread out trimming sessions instead of doing all plants at once. Monitor growth rate to establish the best trimming frequency.

Common Amazon Frogbit Root Issues

Maintaining the balance required for thriving Amazon Frogbit can be tricky. Here are some of the most common root problems and their causes:

Roots Growing Short or Not at All


  • Insufficient lighting
  • Lack of nutrients
  • Water too warm


  • Increase lighting to 0.5-1.5 watts per gallon
  • Add liquid fertilizer with iron & potassium
  • Cool water to 70-82°F range

Roots Turning Brown or Rotting


  • High ammonia levels
  • Low oxygen levels
  • Bacterial or fungal infection


  • Test and change water to lower ammonia
  • Increase surface agitation for gas exchange
  • Treat with anti-fungal or antibiotic if necessary

Roots Detaching From Plant


  • Rapid growth leading to weak attachment
  • Water parameters fluctuating
  • Physical damage from fish nibbling


  • Maintain stable water conditions
  • Trim fast-growing roots
  • Move aggressive fish like goldfish

Roots Clumping Together


  • High humidity causing roots to stick
  • Insufficient water movement
  • Overcrowding


  • Use air-stone to increase water circulation
  • Space Frogbit further apart
  • Manually separate clumped roots

Catching issues early and adjusting will make your Frogbit roots grow lush and long again. Next we’ll compare it to some other popular aquarium plants.

Comparable Aquarium Plants

Amazon Frogbit certainly isn’t the only aquatic plant that produces decorative roots. Here are some other options that can fulfill a similar role:

Red Root Floaters

  • Also a floating plant with the botanical name Phyllanthus fluitans
  • Produces vibrant red roots 4-8 inches long
  • Less dense root structure than Amazon Frogbit
  • Grows slower and less prone to becoming invasive

Rotala Indica

  • Rooted stem plant rather than floating variety
  • Delicate leaves with roots extending 3-6 inches
  • Requires high light and CO2 injection
  • More demanding growth requirements


  • Common rooted aquarium plant also known as Elodea
  • Long green roots extend downwards from stem
  • Fast grower that sometimes sheds lower leaves
  • Not as intricate of root structure as Frogbit


  • Rootless submerged aquatic plant with fine, feather-like foliage
  • Grows as floating or anchored stems up to 10 inches long
  • Provides similar shelter effect for fish
  • Can shed needles that need to be removed

Water Sprite

  • Submerged plant with leaves that emerge to the surface
  • Grows vast root networks from the bottom up to 3 feet long
  • Requires a planted tank setup, not a floating variety
  • Larger plant that needs more space

While other plants have their benefits, none quite match the aesthetic of Amazon Frogbit’s extensive dangling root structure in a floating aquarium plant.

Where to Buy Amazon Frogbit

Amazon Frogbit is one of the most widely available aquatic plants in the aquarium hobby. Both online and local fish stores carry it due to its popularity. Here are some purchasing considerations:

Local Fish Stores

Checking independent aquarium stores in your area is the best option to see the plants in person and get advice. Call ahead to confirm they carry Frogbit in stock.


  • View plants directly
  • Buy only what you need
  • Support local businesses


  • Availability not guaranteed
  • Prices may be higher
  • Limited selection of healthy specimens

Online Retailers

Ordering Frogbit online provides the widest selection and competitive prices, but you can’t see the exact plants being purchased. Reputable sellers will guarantee live arrival.

Recommended Online Sellers:

  • Buceplant.com
  • AquariumPlantsFactory.com
  • JacobsAquarium.com
  • ThatPetPlace.com


  • Wide variety of options
  • Buy in bulk for lowest pricing
  • Plants shipped directly to your door


  • Not able to personally inspect plants beforehand
  • Must pay shipping costs
  • Potential delays or damage during transit

What to Look For When Buying

  • Leaves should be firmly attached and free of blemishes
  • Roots should be long, white and show no signs of rot
  • Look for 6+ leaves per plant for fastest growth
  • Purchase from tanks without signs of algae or pests

Quarantine New Plants

Always quarantine new plants in a separate tank for 1-2 weeks before adding to your aquarium. This prevents the introduction of hitchhiking pests, algae or diseases.

How Many to Buy

For a 10-gallon tank, start with 10-15 individual Frogbit plants. Buying too many is better than not enough since they grow quickly. Extra plants can be removed later.

Following proper quarantine procedures and buying from a reputable source will ensure your new Amazon Frogbit plants establish themselves and start producing lush roots quickly!

Frequently Asked Questions About Amazon Frogbit

Can I Trim the Roots of Amazon Frogbit?

You can! Trimming the roots is not only permissible but often essential for managing the plant’s rapid growth and providing ample swimming space for your fish. A good rule of thumb is to trim the roots back to a length of 2-3 inches. This maintenance should be done every 1-3 weeks.

What Are the Benefits of Amazon Frogbit?

Amazon Frogbit is a powerhouse for phytoremediation, a fancy term for its ability to purify water by absorbing contaminants like heavy metals. Additionally, it’s great at soaking up excessive levels of nitrates and phosphates.

How Long Do Amazon Frogbit Roots Grow?

These roots can stretch up to a whopping 2 feet in the wild! However, in the confined space of an aquarium, they usually range between 5-15 inches.

Why Are Amazon Frogbit Roots Falling Off?

If you’re witnessing a falling root, it’s likely due to turbulent water currents or subpar water conditions. It’s crucial to adjust the water flow and check the water parameters to resolve this issue.

What’s the Size of Amazon Frogbit Roots?

The size can be variable and is influenced by factors like water conditions and tank height. They can grow long and dense, creating a captivating, jungle-like atmosphere in your aquarium.

Does Amazon Frogbit Multiply?

You bet it does! Given the right conditions, Amazon Frogbit can sprout two new leaves on each stem every two days.

Does Frogbit Flower?

While it’s a rare sight in aquariums, Frogbit can indeed produce small, inconspicuous flowers. So, keep an eye out!

What’s the Difference Between Frogbit and Duckweed?

Both are floaters, but Frogbit is the heavyweight champion with larger leaves and longer roots. On the other hand, duckweed is more petite and doesn’t offer the same level of fishy shelter.

Why Are My Frogbit Roots Melting?

Melting roots are usually a red flag for poor water conditions or a lack of essential nutrients. Regular water testing and adjustments are key to preventing this.

How Fast Does Frogbit Multiply?

This plant can grow astonishingly in the right conditions—some even describe it as growing “like a weed.”

What Is Red Root Floater?

Often compared to Frogbit, the Red Root Floater is another floating plant known for its vibrant red roots. These roots are shorter but pack a colorful punch.

Should I Cut Frogbit Roots?

If the roots are cramping your fish’s style or becoming a bit of an eyesore, then yes, a trim is advisable.

Why Are My Frogbit Roots So Long?

Long roots are typically the plant’s way of foraging for nutrients. They tend to grow faster when nitrate levels in the water are on the lower side.

Why Is My Frogbit Dying?

If your Frogbit is declining, the usual suspects are inadequate lighting, poor water conditions, or fish that have developed a taste for your plant.


The aquatic plant Amazon Frogbit can completely transform the look of a freshwater aquarium with its abundant cascading roots. Proper care is needed to allow the roots to flourish and provide shelter for fish, beneficial bacteria, and absorption of excess nutrients.

Monitoring water conditions, nutrients, lighting, and trimming when necessary will prevent common issues. The results are well worth the effort for aesthetic appeal and biological filtration.

With its flowing underwater foliage, Amazon Frogbit remains one of the most popular choices to create a stunning natural aquascape. The plant is readily available from local and online sources to add to your tank.

Incorporating this floating plant brings a touch of the Amazon into your home. Just sit back and enjoy watching your fish interact with and explore the jungle of roots. Amazon Frogbit will keep them active and secure and your water sparkling clear.