Guppy Grass (Najas guadalupensis)

Najas guadalupensis, also known as Guppy Grass, is an increasingly popular choice of plant for aquatic terrariums.

Guppy Grass has a unique set of qualities that make it an excellent aquatic plant.

Its compact shape, bushy green growth, and easy maintenance make it an attractive choice for many aquarium enthusiasts.

In this article, we will discuss all the amazing benefits of Najas guadalupensis and why it makes such a great aquarium plant.

Quick Stats:
Scientific Name Najas guadalupensis
Common Name Guppy grass, Frog grass, Najas Grass
Family Name Najidae
Habitat Tropical Rainforest, Savanna
Temperature 75°F to 85°F
Height 8 to 24 inches
pH 5.0 to 7.5
Lighting Moderate

What is a Guppy Grass?

Najas guadalupensis, also known as guppy grass, is an aquatic plant known for its bright green, slim leaves that look similar to blades of grass.

The leaves are able to stretch up to 4-7 inches in height and look almost jelly-like because of their large air pockets.

It is native to North America and can be found in freshwater ponds and tanks.

The popularity of this plant is due to it being easy to propagate. 

Najas guadalupensis "Guppy Grass" Plant Care Guide

Guppy Grass Facts

Najas guadalupensis is a very slow yet resilient grower and can easily fit into many aquarium setups of different sizes.

It is also great for creating hiding places for small invertebrates as well as providing a cleaner for the water.

This plant has no root system and can feed off the nutrients available in the water instead, simplifying its upkeep. 


Guppy grass has no true stem or roots and grows from thick, furry-like hairs that line the leaves of the plant.

The leaves grow out in all directions, making it look bushy and open which gives plenty of room for movement within the aquarium.

The leaves are hollow and contain large air pockets that help keep the plant afloat.

The color can range from a bright yellowish-green to a deep olive color, depending on the lighting and water conditions. 


Najas guadalupensis is native to North America and is found in freshwater ponds and banks, usually in shallow areas.

It is a hardy plant and can thrive in a wide range of temperatures and pH levels, making it a great plant for many aquariums. 

pH Preference

Guppy grass is able to tolerate acidic, neutral, and alkaline aquariums, making it a perfect fit for both tropical and cold water setups.

It can survive in pH levels from 6.0 to 7.5.

While it can tolerate a wide range of pH levels, the ideal pH is 7.0 with a 0.5 variance. 

Vivarium Type

The Guppy Grass is quite an easy-going species.

With that in mind, it will not be too complicated when it comes to choosing the type of enclosure it is grown in.

It is best to try and replicate the plant’s natural habitat as much as possible.

Doing so will make it easier to provide this foliage plant with its basic needs.

The proper setup and theme of the enclosure will make a big difference to the overall look and health of the plant.

Be sure to choose setups that are moist and high in humidity.

Here are recommended vivariums it will do well in:

    • Paludariums – Half aquatic/ half terrain-based enclosure.

    • Ripariums – Mostly aquatic-based enclosures with some terrain features present.

    • Aquarium– Fully aquatic-based enclosure with little to no dry terrain.

Vivarium Placement

Najas guadalupensis is an aquatic plant and so should be placed in partial or full underwater environments.

Placing it in shallow water, around 1-2 inches deep is the best option so that the nutrient-rich substrate is easy to access. 


Guppy grass does not need a substrate as it has no roots and absorbs nutrients and oxygen directly from the water.

It can, however, be planted onto an aquarium substrate and will attach itself by shallow trapping hairs.

To do so, the nitrogen and phosphate levels in the aquarium should be at optimal levels in order to encourage growth. 


Guppy grass needs an adequate aquarium light source in order to thrive.

Placing the aquarium in an area where it receives bright, indirect sunlight through a window will ensure that the plant receives the photosynthesis it needs to stay healthy.

Artificial lighting can also be used, although LED lighting is preferred as it does not produce unnecessary heat. 

Buy Guppy Grass

When it comes to buying Juncus effusus, there are a few things to keep in mind.

Making sure the plant is healthy when purchased is essential for its success in a vivarium or pond.

Vegetation that is already in poor conditions will have a very hard time adjusting to new environments.

Click the image below to find out more about the current price and other relative info about this plant.

Guppy Grass Care and Propagation

Guppy grass is relatively easy to take care of and requires minimal maintenance.

It can be propagated from just one stem that would develop into multiple plants.

Simply pluck the stem from the source and break it into sections depending on the size needed and place each thoroughly in the aquarium. 

How to Grow

Guppy grass will grow best when it is given the right water and light conditions.

The water should be free of nitrates, ammonia, and phosphates and should also be well-oxygenated and filtered.

Light intensity should also be monitored to ensure that the plant is receiving enough light, but not too much. 

Water Requirements

As guppy grass is submerged underwater, it is important to make sure that the water levels in the aquarium are stable.

The water should not be allowed to deplete too quickly, as this can cause dry pockets in the aquarium.

During regular maintenance, make sure to keep the water levels consistent and clean. 

Plants Similar to Guppy Grass

Adding diversity to an enclosure is key to an aesthetically pleasing setup.

Try mixing up the look of your vivarium with different flora that can easily co-exist in the same types of environment.

Furthermore, if for some reason you find the Guppy Grass hard to acquire or would like to consider something similar to this aquarium plant

Here are other aquatic plants you might find will do well with or in place of Najas guadalupensis :

Rotala indica "Indian Toothcup" Plant Care Guide
Vallisneria spp. "Eelgrass" Plant Care Guide
Bucephalandra spp. "Buce Plant" Plant Care Guide


In conclusion, Najas guadalupensis, or Guppy Grass, is an attractive and low-maintenance aquaria plant.

Its easy-to-care-for nature, bushy green growth, and unique shape make it a great choice for any aquatic setup.

Its popularity is only increasing and its quality traits are highly sought after by aquarists.

Therefore, Guppy Grass should be in consideration for any aquarium owner looking for a low-maintenance, high-quality plant species.

Frequently Asked Questions

Guppy grass, also known as Najas grass, is an aquatic plant used in aquariums to provide a safe hiding and spawning place for fish. It helps keep the water clean, provides oxygen, and absorbs harmful toxins such as ammonia. Guppy grass also serves as a habitat for fry and a food source for many aquarium fish, making it a beneficial and attractive addition to any aquarium.

No, guppy grass is relatively easy to grow. All that is needed is clean water, a warm stable temperature, and a nutrient-rich environment. The guppy grass will quickly spread, making it a great plant for the lowmaintenance aquarium.

No, Guppy Grass does not need to be planted. It can be left to float freely in the aquarium and will spread on its own.

Trim guppy grass by cutting it back just above the roots with scissors or an aquariumsafe grass trimmer. Be sure to remove any clippings to prevent the death of the plant.

Yes, shrimp like guppy grass because it provides hiding places and grazing opportunities for them in the aquarium.

There are several potential causes for guppy grass turning red, including too much light, insufficient nutrients, or high levels of nitrates in the water.

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