How To Grow Duckweed And Know The Tricks

Last Updated on

Duckweed is easy to grow and a nutritious food for fish. You can actually grow duckweed also indoors in a container or outdoors in a ditch or a small pond. Duckweed prefers still water (stagnant), that is why you do not need any complex aeration system as you do in an aquarium tank. It is also advisable for a freshwater aquarium as it absorbs nitrates. What else? You don’t even have to feed duckweed, it is an aquatic plant that absorbs nourishment from the surrounding air.

This tutorial on how to grow duckweed for your aquarium fish will tackle the activities beginning from its preparation until its harvest. At this time, it is ready to feed your fish. Most aquarists prefer the cultivation of duckweed indoors because it is almost effortless to do, especially for those who haven’t much time because of work and other activities. So, we will teach you the indoor culture of duckweed. We hope that after you have performed religiously our tutorial, you could be able to produce your own fish feed without the hassle and continue doing so to make your fish food bill at its minimum.

What You Will Need To Follow This Tutorial

Duckweed growing is not expensive to do, in fact, it is one of the most reasonable food cultivation for aquarium lovers, budget-wise. And since it is packed with nutrients and protein almost equal to a bit of a worm, your fish will grow healthier in a small amount of time. Most of goldfish, tilapia, koi fish, and other fish variety like to eat duckweed and they really love it! Here are the tools you’ll need to culture one of the most nutritious foods for your pet:

  • Rectangular plastic container (at least 5-in. deep, 18-in. length, 12-in. wide).
  • Soft sponge.
  • Clean cotton cloth.
  • Dechlorinated water (20 liters).
  • Aquatic plant fertilizer (such as PondCare brand).
  • Soda straw.
  • Live duckweed (Lemna Minor brand, available in
  • pH Meter.
  • Thermometer.
  • Coffee filter.

Step By Step Instructions

After you have gathered the needed tools and equipment, you are now ready to cultivate duckweed as feed for your fish. Duckweed does not require special caring, unlike any other flowering plants. It will also thrive from soft to hard water condition and from low light to high light. In other words, it is definitely easy to grow duckweed, but you should follow these sets of instructions so that you may not commit mistakes for your first try.

Preparation Of Container

  • Prepare and clean the container that you have bought by scrubbing it with a soft sponge in running water to clear it with any dust particle adhering on all its sides.
  • Do not use detergent or soap.
  • Wipe dry all surfaces of the container.

Pouring Of Water

  • Pour dechlorinated warm water into the container. Tap water treated with water conditioner could also be used when you have this on stock (water conditioner).
  • Make sure that the water does not exceed the 3-inch mark on the container. It would have a 20-liter volume if you reach this height of water.

If You Are Using Tap Water

If you used tap water and treated it with water conditioner, add some aquatic plant fertilizer to nourish the plant. It is also advisable to put decaying plants (from your fish tank) to aid nourishment.

Blow Air To The Mixture

  • Get a clean soda straw at least 12-inch long.
  • Using the straw, blow air into the water to aerate the water slowly. Keep repeating every 10 minutes until enough oxygen is inside the water. The surface water needs to be penetrated by oxygen to be brought even to the bottom of the container to give duckweed its needed aeration. You don’t have to use complex aeration system to aerate the water. This would only be during start up and not continues or if the need arises.

Check The PH Level Of The Water

After a few minutes, once the water is settled, check the pH level using a pH meter. Duckweed thrives at a pH level between 6 and 7.5 and temperature between 50 to 90F. Put the container where this temperature is achievable inside the house.

Adding duckweed

After the above conditions are met, you are now ready to add the duckweed into the mixture.

  • Scatter enough amount of the tiny plant at the surface of the water, covering at least 3/4 of the water surface. This will allow natural light and oxygen to enter into the container. Do not cover the container as duckweed needs lots of oxygen.
  • After several minutes, you will notice that the duckweed starts to spread out of the surface of the water and some at the bottom begin to rise on the surface.

Harvesting Duckweed As Fish Food

Duckweed grows at a fast rate. You could harvest from the container 2-4 days after you set it up. These are the following steps to harvest duckweed correctly so that you could have sufficient supply of this tiny plant for your fish:

  • Get a clean coffee filter, then scoop some duckweed from the container.
  • Bring the filtered duckweed into the aquarium then pour its content, occasionally shaking the coffee filter while it is submerged in the fish tank. Make sure that the coffee filter is fully empty before you get another batch. The fish will devour this plant as this is really delicious for them.
  • Continue feeding your fish until they like eating or an amount just enough for their dinner. Stop feeding them with duckweed when you notice a sign that they are full. The duckweed that remains in the container will continue to grow until the water is not sufficient enough to sustain their growth, at this time you can start another cycle.


Did you enjoy this tutorial? You really don’t have to exert much effort in growing duckweed for your fish. Even the waiting time is not too long, your fish will have an instant feed in no time, fresh and nutritious, too! Like and share this article with your friends and loved ones, especially those who are avid fish lovers and give some comments if you really like our useful tutorial we shared with you.

1 thought on “How To Grow Duckweed And Know The Tricks

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.