7 Toxic Plants For Betta Fish: Plus 3 Safe Alternatives

I'm sure you’ve seen online that some plants can be toxic to your betta fish and need to be avoided. In this article, I'll give you the lowdown on which plants to avoid and some safe alternatives, so you won't accidentally poison your finned friend!
Toxic Plants For Betta Fish Top Image

There’s a lot of information online about toxic plants for betta fish. Some of it is accurate, and some of it is a little misleading.

In this post, I’ll advise you on which plants to avoid using in your betta tank, and which plants are safe to use.

But, before we go any further:

Quick disclaimer, I’m not a vet, just an avid fishkeeper. This is my opinion based on personal experience.

First up, the word toxic. We all instantly assume toxic means death. There are actually various degrees of toxicity, the symptoms of which range anywhere from mild irritation to death, and anywhere in between.

Certain plants, like peace lilies and pothos for example, contain toxic calcium oxalate crystals that can cause irritation and swelling in the mouth and throat of your fish if ingested.

In large quantities, they can really open up a can of whoop ass on your betta’s central nervous system.

The trick to using these plants safely in a betta tank is:

Keep only the plant roots in the water.

The plant’s leaves and stems should stay out of the water, otherwise, they will die and begin to break down, releasing poisonous calcium oxalate crystals into your water. Keep them dry and this won’t happen.

Keep your betta fish well fed so they don’t eat the plants.

Betta fish need a protein-rich diet, which means they can’t survive on plant matter. If they get hungry enough, they may start nibbling on the plant’s roots in search of food.

To prevent this, make sure to feed your betta fish regularly to keep them satisfied and prevent them from seeking nourishment from the plant roots.

Toxic Plants For Betta Fish (aka Siamese Fighting Fish)

The following plants can be harmful to betta fish, so you should avoid these toxic plants to keep your betta safe and healthy.

1. Water Hemlock

Water Hemlock

According to the United States Department of Agriculture website, water hemlock is “the most violently toxic plant in North America”

Only a small amount of the toxic substance in the plant is needed to produce poisoning in livestock or in humans.

With that in mind, it goes without saying this is one of the most toxic plants and you shouldn’t go anywhere near it yourself, let alone introduce it to your betta’s tank.

2. Rue


The Rue plant is among the most toxic plants, it contains a compound called psoralen, which can cause skin irritation, photosensitivity, and even kill your betta.

So it goes without saying it’s best to avoid using Rue in your betta tank or any aquarium.

3. Hygrophila Balsamica

Hygrophila Balsamica

Hygrophila Balsamica can be grown in 2 ways, emersed or submerged.

In its emersed form (aquatic plant reaching above the surface of the water), it releases a highly toxic sap into the water and should be avoided.

Hygrophila balsamica would be safe if it was grown submerged (underwater), but keep a close eye on its growth, so that it doesn’t grow above the surface of the water.

I personally wouldn’t risk using this plant in an aquarium as there are much safer alternatives available. If you do decide to use this plant, it requires a good amount of light and high CO2 content.

4. Dieffenbachia (Dumb Cane)

Dumb Cane Plant

Dumb Cane are popular house plants but need to be kept out of reach of your betta fish (or any other pets or children).

The sap contains a strong irritant and causes the throat and vocal cords to swell up if ingested, leaving you unable to speak for up to 2 weeks!

This is one of the toxic plants that needs to be avoided.

5. Peace Lilies

Peace lilly

Peace lilies contain calcium oxalate crystals and are one of those plants often seen in betta fish vases.

Please don’t keep a betta in a vase or small bowl, they need a proper tank with a minimum capacity of 5 gallons, preferably 10 gallons.

Bettas are labyrinth fish, which means they have to breathe air at the water’s surface from time to time. When you keep a betta in a small vase and add any type of plant, the plant blocks the water’s surface so there’s little to nowhere for your betta to take in this air.

On top of that, there’s no space for a heater in a vase, and a betta requires water to be 78°-82° F / 25.5°-27.7°C. Cold water + a lack of air doesn’t make for a happy and healthy betta.

6. Water Lettuce

Water Lettuce

Water lettuce is a floating plant that contains calcium oxalate crystals. If properly maintained it’s OK to use in a large aquarium.

This plant does grow rather large and can take over your aquarium pretty quickly, so it’s not ideal for the smaller fish tanks that Bettas are usually kept in.

Because it is a floating plant, it can quickly cover the surface of the water, making it difficult for your betta fish to breathe in air at the surface.

7. Pothos (aka Devil’s Ivy)


I’ve seen plenty of comments online saying Pothos is toxic to Betta fish. I’ve kept a betta in a 10-gallon tank, with a pothos plant, and never experienced any problems.

It has the potential to be toxic because the plant contains insoluble calcium oxalate in its leaves, but if you keep the leaves out of the water and only have the roots submerged, you shouldn’t have any issues, I’ll leave it up to you to decide whether you want to add this plant in with your Betta.

How To Use A Pothos Plant In Your Aquarium

Effects of Toxic Plants on Betta Fish

Some plants contain toxic chemicals or substances, such as calcium oxalate crystals or psoralen, that can lead to poisoning or even death of your betta fish.

Let’s look at the symptoms and their impact on the central nervous system.

Poisoning Symptoms

Some plants contain calcium oxalate crystals that can cause irritation and swelling in the mouth and throat of your fish. As a result, breathing becomes difficult for them.

If you notice signs of distress, such as erratic swimming or gasping, you should remove the harmful plant from the tank and seek veterinary assistance for treating your fish.

If you need to seek veterinary advice you can find a specialist aquatic vet in your area using the links below:

Convulsions and Physical Effects

Another toxic substance, cicutoxin, found in some plants can cause convulsions and muscle tremors in betta fish.

If you observe your fish exhibiting rapid or jerky movements, remove any potentially harmful plants, check your water parameters, and monitor closely for other health issues.

Central Nervous System Impact

Some plants contain saponins, which could negatively impact the central nervous system in betta fish when ingested.

Harmful saponins will cause irritation and swelling, potentially impairing your betta’s ability to swim or feed properly.

If your fish is struggling to maintain balance or shows signs of disorientation, this could be an indication of toxin exposure or possible swim bladder disease.

Best Plants for Betta Fish That Are Safe

Now we’ve gone over which plants to avoid or use with care, we’ll go over my top 3 choices perfect for betta tanks and are safe for all aquatic life.

Whether you choose live or fake, adding plants to your betta tank will provide many benefits. Live aquatic plants also have the added benefit of absorbing nitrates from the water.

1. Anubias


  • Name / Scientific Name: Anubias / Anubias barteri
  • Difficulty: Easy
  • Growth Rate: Slow
  • Max Height: 4-12 inches
  • Lighting Requirements: Low
  • CO2: Low
  • Substrate Required: No

Anubias is an ideal choice for your betta aquarium due to its hardy nature, low light requirements, and lovely broad leaves.

This slow-growing, safe plant is easy to care for and can be attached to driftwood, rocks, or decorations, providing excellent hiding and resting spots for your betta fish.

Betta fish love the broad leaves of this plant, you’ll soon see your betta chilling out and getting some rest on its favorite leaf!

Anubias also do a great job of cleaning the water by absorbing nitrates.

2. Java Moss

Java Moss

  • Name / Scientific Name: Java Moss / Taxiphyllum barbieri
  • Difficulty: Easy
  • Growth Rate: Fast
  • Max Height: 5 inches
  • Lighting Requirements: Low
  • CO2: Low
  • Substrate Required: No

Java Moss is another fantastic choice. Its versatility and low light tolerance make it suitable for various tank setups.

Java Moss easily attaches to surfaces like rocks or driftwood, creating a natural-looking environment for your fish.

One of the significant benefits of Java Moss is its ability to provide cover for betta fish.

It also does a great job of keeping the water quality in check by filtering out particles and absorbing excess nitrates.

3. Moss Balls

Betta Moss Ball

Moss balls are unique and beneficial additions to your betta fish aquarium. These spherical algae balls help to oxygenate the water, remove nitrates, and inhibit the growth of undesirable algae. 

They require minimal care – just make sure they receive low to moderate light and occasionally roll them in your hands to maintain their round shape.

These fascinating aquatic plants not only improve the water quality but also provide visual interest and stimulation for your betta fish.

Managing Plant Decay

As plants decay, they can release toxic chemicals into the water.

Cleaning your tank, performing water changes, and removing any dead leaves or excess foliage on a regular basis will help maintain water quality and reduce the risk of toxicity.

Alternatives to Live Plants – Fake Plants

If you’re concerned about potential risks associated with having live plants in your betta fish tank, you could opt for fake plants.

Silk plants are a safer option as they won’t introduce toxins, saponins, or harmful bacteria that could affect your fish’s overall health.

If you choose plastic plants, make sure they are specifically designed for aquarium use and have no sharp edges that could injure your betta’s fins.

Final Thoughts on Plants Toxic To Betta Fish…

Now we’ve established which plants are toxic to bettas (or any other aquarium fish), which can be used with caution, and most importantly which plants are safe for bettas, you should have a good idea of which plants you’d like to add – my personal favorite (and my bettas!) is the Anubias plant.

Check out the aquascaping section for more plant guides and the aquarium health section for lots of great tips and guides for fish owners.

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Hey, fellow fish enthusiast 👋! I'm Paul and I've been an aquarium addict since I won my first goldfish at the fair many years ago. Let me share with you the knowledge that I've gained along the way (and avoid the mistakes I've made!), so you too can create an underwater paradise for your aquatic friends.