10 Best Plants to Purify Aquarium Water

A planted tank has a jungle-look that brightens up any room. Besides the vibrant aesthetics, aquatic plants provide natural filtration for aquariums.

by Fabian

Updated: June 22, 2020 / 6 mins read

Fabian is the dedicated Chief Editor at Aquarium Nexus. From a young age, he was captivated by the vibrant world of aquatic life, leading him to accumulate over 20 years of experience in keeping and breeding various fish species. The fulfillment derived from the aquarium hobby has remained a constant throughout Fabian's life. As an expert in the field, he finds great pleasure in imparting his extensive knowledge and personal experiences to both seasoned aficionados and budding enthusiasts.

Plants absorb nutrients from the water and prevent algal blooms while providing hiding spaces for fry and fish.

You can either choose submerged or emergent varieties, depending on your aquarium layout. Some of the best plants for the purification of aquarium water include:

1. Duckweed

Duckweed

Duckweed stays hungry for nutrients like nitrogen and phosphates, and its rapid growth rate will maintain your aquarium’s water quality.

The plant will thrive in tanks with plenty of organic matter, and it will discourage algae growth.

If you need to maintain a cool aquarium, you can let duckweed spread over a significant part of the tank’s surface. Do not let it completely cover the top of the aquarium because it will block light from getting to the other tank’s inhabitants.

Duckweeds thrive in still waters, and you should not place them amidst strong currents. The plant is rich in protein, and fish like koi fish, goldfish, and grass carp may feed on it.

2. Amazon frogbit

Amazon Frogbit

The Amazon frogbit is a classic among aquarists who keep planted tanks. The plant is characterized by large rosettes and long roots that provide a refuge for shy fish, invertebrates, and fry.

These roots can sometimes get caught up in filters and decorations, and you may need to bind the plant to one side of the aquarium.

This floating plant will purify your tank water, but it can quickly overrun the aquarium. You will need to prune it every week or two, especially if your tank has a lot of nutrients.

The Amazon frogbit blocks out a substantial amount of light, and you can match with fish that like dull environments like bettas.

3. Waterweeds

Waterweed is sold under many different names, including Anacharis, Elodea, and American or Canadian waterweed. You can choose to plant it in the substrate or leave it floating.

If you don’t want to keep it anchored, you will have to keep it up with its rapid growth rate as it naturally seeks the light source.

The plant absorbs nitrates, phosphates, and CO2 through the leaves, while the roots feed on debris and fish waste from the substrate. Propagation is as easy as taking cuttings from the mother plant.

4. Guppy Grass

Guppy Grass

Guppy grass (Najas guadalupensis) is a common plant in freshwater and brackish water bodies across North and South America.

It was named for the hiding spaces it provides for young guppies as well for other fish like tetras, rainbow fish, and danios. The plant traps detritus that shrimp and fry feed on.

Guppy grass is quite hardy, and it can thrive without CO2 injection. Keep the temperature between 68-79 °F with the PH at 6.0-8.0.

It will thrive in medium lighting, where it will exhibit lush green leaves. Guppy grass will feed on any nutrient in your aquarium, including ammonia, nitrites, and nitrates.

5. Hornwort

Hornwort

The purification abilities of hornwort have made it popular in the aquarium trade.

In the wild, hornwort exhibits a high tolerance for a wide range of habitats, and it has been recorded in all continents apart from Antarctica.

A single hornwort plant will have many stems from which whorls of green leaves emerge.

You can keep it floated or anchored, depending on how you want to style your aquarium.

Hornwort will absorb ammonia, nitrates, CO2, and phosphates and oxygenate the aquarium water. Its dense leaves present an excellent spot for fish to lay their eggs.

6. Water Lettuce

Dwarf Water Lettuce

Water lettuce is a popular floating variety in aquariums. While it is thought to have originated on the Nile River, it has since spread across the world.

Its invasive characteristic has made it banned in some states, and you will need to check the local regulations of your area.

The plant is named for its rosettes that resemble small lettuce heads. The leaves are covered in tiny hairs that promote buoyancy, and the plant can easily create mats that overrun a fish tank.

Water lettuce gets its nutrients from the water, and it is popularly used to combat algae. Its roots also provide hiding spots for fry.

7. Water Sprite

Water Sprite

Water sprite, or Indian Fern, is known for growing surprisingly fast. It can grow either floated or anchored, which gives you room to play around with your tank’s aesthetics.

If you decide to float it, you only need to add the stems and leaves into the water. It has thin roots that trap debris for fish and shrimp to snack on.

Water sprite have delicate leaves that do not like strong currents.

The ideal temperature range is 68-82 °F with the PH at 6.0-7.5. Trim the outer stems regularly so that it does not overcrowd your aquarium.

8. Water Hyacinth

Water Hyacinth

Water hyacinth is popularly known as an invasive plant in the wild, but its ornamental allure has made it a favorite among aquarists.

It has thick and glossy leaves that emerge from the water and pink, violet, or blue flowers. Water hyacinth requires a lot of light, and it also likes to be crowded.

9. Pearl Weed

Pearl weed is an excellent low-light carpet plant for beginner aquariums. It has a bright green hue that will be perfect in the foreground or mid-ground.

You can shape it how you like during regular pruning as it can grow quite fast. During propagation, all you need to do is cut the stem ends, clump them together, and bury them in the tank’s substrate.

10. Pothos Plant

Pothos Plant

The pothos plant may not be an aquatic plant, but its roots are perfect for natural filtration.

Leave the roots in the water and use the aquarium lid to ensure that it does not fall in the tank.

You can also stick the plant in a hang-on-back filter. The plant will absorb a lot of nitrates and discourage algae growth.

Can You Use Plants to Filter Aquarium Water?

It is possible to maintain a thriving planted aquarium without a filter, although it can be challenging to set it up. You want to keep a few livestock so that the plants can handle the tank’s bio-load.

Conclusion

Planted tanks bring a slice of the underworld to our homes. While there are many aquatic plants in pet stores to choose from, you can request for purifying varieties that will remove toxic materials and promote good water quality.