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How to Get Rid of Nematodes on Freshwater Plant

Updated: April 2, 2022

Freshwater plants are a great addition to any aquarium or pond. They provide natural filtration and oxygenation, and they also add beauty and visual interest to the water. However, freshwater plants are not immune to pests and infestations, and one of the most common problems in aquatic plant culture is nematodes.

Nematodes are small, worm-like creatures that feed on plant roots, causing stunted growth, yellowing leaves, and eventually death. If you notice that your freshwater plants aren’t thriving as they should, there’s a good chance that nematodes are the culprit. Fortunately, there are several ways to get rid of nematodes on freshwater plants.

Identify the problem

Before you try to get rid of nematodes, you need to be sure that they are the problem. There are many other reasons why your freshwater plants may not be doing well, including poor water quality, inadequate lighting, and nutrient deficiencies. Examine your plants carefully for signs of nematode infestation. The symptoms include:

  • Stunted growth
  • Yellowing leaves
  • Wilting or drooping
  • Root damage

If you see any of these signs, carefully remove the plant from the water (use gloves if necessary) and examine the roots for signs of nematodes. They will look like tiny white worms.

Remove infected plants

The first step in getting rid of nematodes is to remove any infected plants from the water. This will prevent the nematodes from spreading to other healthy plants. Carefully remove the infected plant from the water and dispose of it in a plastic bag or sealable container.

Sterilize equipment

Once you have removed the infected plant, it’s important to sterilize any equipment that came into contact with it. This includes nets, scissors, and any other tools you used to remove the plant. Soak the equipment in a solution of bleach and water (one part bleach to nine parts water) for at least 30 minutes. Rinse the equipment thoroughly with clean water before using it again.

Use a nematode-killing solution

There are several products on the market that are designed to kill nematodes on freshwater plants. These solutions typically contain a chemical called fenamiphos, which is toxic to nematodes but safe for plants and fish when used according to the instructions.

To use a nematode-killing solution, carefully remove the infected plant from the water and rinse the roots under running water. Mix the solution according to the instructions on the label and soak the roots for the recommended amount of time. Rinse the roots thoroughly with clean water before placing the plant back in the water.

Use natural remedies

If you prefer to avoid chemicals, there are several natural remedies that can help get rid of nematodes on freshwater plants. One of the most effective is to use nematode-resistant plants as a companion for your freshwater plants. These plants release compounds that repel nematodes, preventing them from attacking your other plants.

Another natural remedy is to use beneficial nematodes. These are microscopic worms that feed on nematodes and other harmful pests in the soil. You can purchase beneficial nematodes online or at your local garden center.

Maintain good water quality

Finally, it’s important to maintain good water quality in your aquarium or pond. Nematodes thrive in dirty, stagnant water, so keeping your water clean and well-oxygenated will help prevent infestations. Test your water regularly and make any necessary adjustments to keep the pH, ammonia, nitrite, and nitrate levels within a healthy range.


Are nematodes harmful to fish?
No, nematodes do not pose a direct threat to fish. However, they can indirectly harm fish by damaging the roots of freshwater plants, which can lead to poor water quality and stress for the fish.

Can nematodes be prevented?
Yes, there are several ways to prevent nematode infestations. Maintaining good water quality, using nematode-resistant plants, and avoiding overfeeding can all help prevent nematodes from becoming a problem.

Can I use vinegar to sterilize my equipment?
No, vinegar is not an effective sterilizing agent for aquatic equipment. Use bleach and water instead, following the instructions in the article.