Amazon Frogbit – Care, Growth, Propagation, Light, Maintenance

The Amazon frogbit (Limnobium laevigatum), also called the smooth frogbit, is a popular floating plant in aquariums. The plant is sometimes called the South American sponge plant thanks to the spongy undersides on its leaves that promote buoyancy.

It is easy to mistake the Amazon frogbit with the water hyacinth because they both have round, bright-green leaves. The plant’s ornamental characteristics and low maintenance make it popular among aquarists.

As an ornamental plant, it is often found in aquariums and ponds or wet places in their natural habitat. The younger plants develop leaves that stay flat on the water surface, while the older plants grow their leaves above the surface of the water. Their flowers are somehow whitish, making them one of the most adorable floating plants available.

Below is everything you need to know about the Amazon frogbit:

Amazon Frogbit Origin

The Amazon frogbit was first described by a French biologist in 1814. It was named after the Greek word ‘limnobios,’ which translates to ‘dwelling in a lake.’

The plant is native to the freshwaters of Central and South America, although its rapid growth rate has made it a nuisance in many countries. In the US, the plant is common in California, where it has become invasive because of the aquarium trade.

Before buying the plant, look up the local and state regulations to determine if you need a license. You should also dispose of the plant responsibly and avoid letting it overgrow in outdoor ponds. 

Amazon Frogbit Appearance

amazon-frogbitThe Amazon frogbit does not ship well because its roots easily break off. The leaves may also appear melted if they got flipped into the water during transit.

If your plant arrives in bad shape, you can nurse it back to health with only a handful of healthy leaves with roots.

The plant can easily reach 20 inches in a fish tank and cover the entire water surface. The leaves on the young plants lie prostrate on the water, and they emerge above the water as the plant matures.

In the aquarium, the leaves will grow to about 1-2 cm in diameter. Although the plant can snowball, it is easier to remove when compared to other floating plants like duckweed.

The Amazon plant remains buoyant due to a bloated underside that appears silvery. Its flowers are tiny, white, and unisexual.

The plant grows thick roots, from which strands of fine root hairs emerge. An aquarium with the Amazon frogbit can appear cloudy because of the root hairs.

The roots not only trap debris, but they provide a surface for the growth of beneficial bacteria. Fry and shrimp can feed on the organic matter trapped by these roots, although you will have to rinse them out once in a while.

The roots can grow up to a foot in length, and if left unchecked, can reach the substrate, filter, and decorations. Do not hesitate to prune the Amazon frogbit’s roots since they will grow thicker than before.

Amazon Frogbit Water & Light Requirements

The Amazon frogbit is easy to keep because it thrives in a diverse range of water conditions. In the wild, the plant is adapted to soft water, and you should maintain a PH of 6-7.5.

The plant will tolerate a temperature range of 68-86 °F. If kept in colder environments, the plant’s growth rate is reduced, and it produces smaller leaves.

The Amazon frogbit will be exposed to bright lighting since it is a floating plant. While the plant will be fine with 12 hours of light, it can easily get scorched if the light is too intense.

You can use LED lights instead of incandescent bulbs, which tend to burn too hot. The plant will also be fine with full-spectrum T8 or T5 bulbs.

Amazon Frogbit Maintenance

The most important thing to practice with the Amazon frogbit is keeping the top of the leaves dry. Avoid wetting the top of the plant by being extra careful when performing water changes. Regular water changes are necessary because the plant also rots in stale water.

The plant prefers a gentle current since it is a floating species, and a lot of water movement may break their roots. Since it is exposed to the surface, CO2 supplementation is not necessary. You may, however, have to add fertilizers if the tank water is low in nutrients.

You need to prune the Amazon frogbit regularly because it can readily overrun your aquarium. When this happens, other plants in the aquarium will not absorb sufficient light.

Your fish may also suffocate if there is no surface agitation to boost oxygenation. You can determine if your fish are not getting enough oxygen if you see them gasping at the water’s surface, or they appear lethargic in the tank.

It can be challenging to keep the plant with snails since they like to feast on the spongy undersides. A few snails may not do enough damage to kill the plant, but it will not survive in a tank populated with the invertebrates. If you have to keep snails, opt for plant-friendly varieties like the Malaysian Trumpet Snail.

Amazon Frogbit Propagation

In the wild, the Amazon frogbit reproduces through seed production and pollination. In an aquarium setting, however, the plant will produce new plantlets. The baby plants will stay linked to the mother plant, and they will receive nutrients until they are ready to break away.

Once mature, the plant can be used in aquascaping in ponds or aquariums. Amazon frogbit is usually added to the tank as an ornamental plant. It has the ability to grow fast and cover the surface of the tank within a short time. The plant’s round-like leaves float beautifully on the water surface, creating an amazing scene.

Since young Amazon frogbits will develop flat leaves that float freely on the surface of the water, they make a wonderful addition to the aquarium. Keep in mind that older plants are more likely to exhibit elegant and vibrant flowers.

These flowers are usually white in color and their presence in the aquarium will change the entire tank set up into something truly attractive. That’s why they are used as ornamental plants in aquariums and ponds.


If you want a floating plant that is beginner-friendly, consider getting the Amazon frogbit. It is easy to maintain, and it will proliferate in ideal conditions.

The plant is, however, notorious for depleting oxygen in a fish tank, and you will need to prune it regularly.

Aquarium Plants   Updated: June 24, 2020
avatar Hello, my name is Fabian, and I am the Chief Editor at Aquarium Nexus. I have over 20 years of experience in keeping and breeding fish. The aquarium hobby brings me immense joy, and I take great pleasure in sharing my experiences with others.

Leave a Comment

Your email address will not be published. Required fields are marked *