Salvinia Vs Duckweed – The Battle Of The Floating Plants!

Salvinia and duckweed are both popular floating plants in the fish-keeping hobby. However, I prefer Salvinia because it is easier to manage and remove when necessary.

After publishing my article on floating plants for aquariums, many readers requested a specific comparison between Salvinia and Duckweed.

Since I keep both plants in my tanks, I wanted to share my experiences.

Salvinia

Salvinia In My Tank
Salvinia In My Tank

Pros

  • Easy Maintenance
  • Great Water Purification

Cons

  • Can Be Difficult To Find
  • Often Missold

Several types of Salvinia are available in the aquarium hobby, with Salvinia auriculata being the most common variant.

It’s important to note that Salvinia is often mislabeled. Even if you purchase something labeled as Salvinia natans or Salvinia minima, there’s a good chance it’s Salvinia auriculata.

The primary advantage of Salvinia over duckweed is its ease of maintenance. The larger leaves make it simpler to remove from your tank when necessary, allowing you to grab and remove fistfuls of excess Salvinia.

The main disadvantage when comparing Salvinia to duckweed is that Salvinia can be difficult to find in some areas, and even when available, it is often double the price of duckweed.

Despite this, I love this plant and recently used Salvinia as my floating plant of choice for my aquariums due to its excellent water purification and easy maintenance.

Duckweed

Duckweed In My Tank
Duckweed In My Tank

Pros

  • Great Water Purification
  • Cheap Or Free

Cons

  • Maintenance Is A Pain
  • Rapid Growth Rate

There are several varieties of duckweed, with common duckweed (Lemna minor) being the most prevalent in the fish-keeping hobby.

The primary advantage of duckweed over Salvinia is its rapid growth rate, as it quickly absorbs excess nutrients in your tank.

However, the main drawback of duckweed is its persistence. Once introduced to your aquarium, it’s very difficult to remove, and a single remaining plant can quickly propagate and cover the surface again.

Despite this, duckweed provides excellent natural water purification by rapidly consuming nitrogen compounds and excess phosphate.

Additionally, duckweed is often available for free from public ponds. It’s a hardy plant that thrives in various environments and grows so quickly that taking a small amount from a pond will be replaced within a day.

Benefits To The Aquarium

Salvinia In One Of My Aquariums
Salvinia In One Of My Aquariums

Salvinia and duckweed offer numerous advantages for your aquarium, making them valuable additions.

The primary benefits of keeping Salvinia and duckweed in your tank include:

  • Natural water purification
  • Providing shade for fish
  • Creating grazing areas for shrimp

Depending on your specific tank setup, some of these benefits may be more relevant than others. However, the universal benefit for all tank setups is their contribution to water purification.

Water Purification

Duckweed In One Of My Tanks
Duckweed In One Of My Tanks

Water purification is the process of removing ammonia, nitrite, and nitrate from your aquarium water to ensure safe and stable conditions for your fish.

Even trace amounts of ammonia or nitrite can be harmful, but Salvinia and duckweed rapidly absorb ammonium and nitrate, and in some cases nitrite.

Managing Total Dissolved Solids (TDS) becomes crucial when keeping shrimp or sensitive fish. Floating plants like Salvinia and duckweed can help manage TDS by absorbing excess minerals in the water.

You don’t need to fully cover the surface of your tank to reap these benefits—a small amount of either floating plant can effectively contribute to water purification.

Shade For Fish

Salvinia In My Betta Tank
Salvinia In My Betta Tank

Both Salvinia and duckweed are excellent for providing shade for the fish in your tank.

Wild fish fear predation from above by birds, so floating plants keep your fish calm and relaxed.

My betta fish, gourami, tetras, and rasboras are more confident and willing to swim around their tanks when floating plants are present.

Grazing Areas For Shrimp

An underrated advantage of floating plants is the grazing areas they provide shrimp.

Salvinia and duckweed are excellent for this because algae and biofilm form on the undersides of the plants, serving as a food source for the shrimp.

If you have shrimp in your tanks, you’ll soon see them upside-down, grazing on your floating plants.

Additionally, small particles of fish food often get trapped among the floating plants, and my shrimp snatch the food and head off to a hiding spot to eat it.

Growth Rate

Duckweed In One Of My Aquariums
Duckweed In One Of My Aquariums

Salvinia and duckweed have rapid growth rates, but in my experience, duckweed grows way faster.

Research by the Indian Academy of Sciences found that duckweed could increase its mass by 25% in just 5 days.

Initially, I thought this would mean duckweed would absorb more ammonium and nitrate compared to the slightly slower-growing Salvinia.

However, despite duckweed’s faster growth rate, the larger size of Salvinia could still result in it absorbing just as much, if not more, nitrogen compounds from your tank water.

Maintenance

Salvinia In A Floating Plant Ring
Salvinia In A Floating Plant Ring

Due to the rapid growth rate of Salvinia and duckweed, regular maintenance is necessary to prevent them from dominating your tank.

While these plants offer excellent benefits for water purification, allowing them to cover too much of the tank’s surface can hinder light penetration, affecting the health of your submerged plants.

That’s why I use floating plant rings in many of my tanks, which helps me position my floating plants to ensure light can still reach the submerged plants.

Removing Salvinia From My Aquarium

Salvinia is one of the easiest floating plants to maintain and you can remove it by the handful.

This makes maintenance quick and easy, usually taking me less than a minute to clear out excess Salvinia from my aquariums.

Additionally, the larger leaf size compared to duckweed makes Salvinia much easier to remove from your tank.

Removing Duckweed From My Aquarium

Removing duckweed from your aquarium can be challenging, but the comb method has proven effective.

This simple and cheap technique uses a hair comb to scoop up the duckweed while allowing excess water to pass through the comb’s teeth.

The leaves of duckweed can be difficult to completely remove, and people believe that once duckweed enters your tank, it remains until you completely re-scape it.

Final Thoughts

Salvinia and Duckweed provide similar benefits, but in my experience, Salvinia is the superior choice due to its ease of maintenance.

Although Salvinia can be harder to find and is typically more expensive than Duckweed, the simplicity of its upkeep makes it worth the extra effort and cost.

If you’re deciding between Salvinia and Duckweed for your aquarium, I recommend opting for Salvinia to save yourself some trouble.