Those who keep fish, whether in an aquarium or a backyard pond, understand the necessity of keeping the water clean, limiting algae, and providing adequate nutrition to the fish. Common duckweed, a tiny floating plant, can do all of this. While some perceive duckweed as a nuisance, its benefits often exceed the drawbacks. Many people who maintain fish want to learn more about it and how to produce it in ponds or aquariums.
- What is Duckweed?
- How to Grow Duckweed in a Container
- How to Control Duckweed in Aquarium
- Benefits of Duckweed in Aquarium (What is duckweed used for in fish tank?)
What is Duckweed?
Duckweed is one of the tiniest flowering plants, about 1/16 to 1/8 of an inch (.159 -.318 cm) in length, and found almost everywhere in water habitats. It has one to three flat, oval-shaped light green leaves. It thrives in stagnant water, forming dense colonies on the surface.
Its rapid divisional reproduction might be a boon or a curse. Rapid growth provides a cost-effective and healthy food source for fish. In addition, it absorbs harmful nitrates and other pollutants from the water, improving water quality, and lowering the light that algae feed on due to its growing canopy.
On the other hand, duckweed can swiftly overwhelm a pond if left unchecked, depriving fish of oxygen and lowering aquatic plants of sunlight.
Duckweed may be found in the pond in a variety of kinds. Duckweeds are classed based on their many roots in this quick guide, so start there. Then, based on the size, shape, and color of the leaves, determine which species you are dealing with.
Rootless Duckweed (Wolffia arrhiza)
This kind of duckweed doesn’t have roots. Instead, the leaves are oval-shaped and 0.5-2 mm in length and fat. They have the appearance of tiny bright green grapes.
Greater Duckweed (Spirodela polyrhiza)
Each leaf has several roots. Flat, 4-12 mm length, roughly spherical or tear-shaped leaves. The leaf’s top surface is dark green and smooth or slightly ribbed. There’s a reddish red underneath.
Fat Duckweed (Lemna gibba)
The leaves are 2-6 mm long and domed. The leaf’s top surface is a drab green or reddish-brown color. Underneath the leaf, look for large, bubble-like transparent cells.
Least Duckweed (Lemna minuta)
Flat, 1-2.5 mm long leaves. The color of both leaf surfaces is a mild grey-green. The leaf is thin and virtually transparent.
Common Duckweed (Lemna minor)
Flat, egg-shaped leaves with a length of 2-7 mm. The leaf’s top surface is a vivid yellow-green color. In contrast to Least Duckweed, the underside is significantly lighter.
Ivy-leaved Duckweed (Lemna trisulca)
The leaves are 5-10 mm in length and flat. Each leaf has a stalk that connects it to neighboring leaves and a pointy tip. Leaves grow in threes, are transparent, and float just below the water’s surface. There is never more than one root. There are times when there are no roots at all.
How to Grow Duckweed in a Container
Duckweed is an easy-to-grow plant that provides natural food for various animals while also preventing mosquito breeding on the water. You can grow duckweed indoors or outside in a pond to cultivate it for a research project, animal feed, or fun.
1. Purchase at a pet store or harvested from a pond.
You might be able to find duckweed in your local pet store or take it from a pond where it is growing. First, fill your container halfway with pond water. Then, scrape some duckweed from the pond and place it in your container with your hand.
While bringing the duckweed home, cover the container with the lid to prevent splashing. Because duckweed pods sprout and reproduce swiftly, 50-100 should be plenty.
2. Disinfect the duckweed.
To disinfect the duckweed, you’ll need potassium permanganate. In 12 gallons (45 L) of water, dissolve one teaspoon of this chemical. Place the plant for thirty seconds in the permanganate solution.
Potassium permanganate is available at most pharmacies. The duckweed will be free of bugs and bacteria after being disinfected.
3. Put the duckweed in a container.
Place the plant in a container with a depth of 12–14 inches (30–36 cm). This will assist you in creating an ideal atmosphere for the duckweed to flourish. Fill the dish halfway with new water, and then add the duckweed. Use fresh water from a pond for optimal results, but tap water will suffice.
4. Place the tray where it will receive 10 hours of sunshine per day.
It would be best to place the tray next to a window that receives at least 10 hours of sunshine per day. Duckweed, like many other plants, thrives in direct daylight.
Suppose you don’t have access to a window that receives 10 hours of sunlight. In that case, you can help it grow by using fluorescent light bulbs. Place the light bulbs 15 inches (38 cm) above the tray for optimal results. But always remember that duckweed will not develop as well as it should with direct sunlight.
5. After one week, change the water in the tray.
Check the tray several times a day for damaged duckweed and remove it. In addition, you should add more freshwater to the tray. Duckweeds will take around ten days to multiply.
6. Transfer the duplicated duckweed to your selected spot using a net.
If you’re relocating the duckweed to a backyard pond, make sure the pond gets enough sunlight. If you’re transferring the duckweed to an aquarium, ensure the aquarium lid is equipped with a light source.
Once in your pond or aquarium, duckweed requires no additional care or upkeep.
How to Control Duckweed in Aquarium
Duckweeds deprive aquatic plants and water creatures (including fish) of oxygen when they blanket the surface to a greater extent. These weeds thrive in bodies of water with high levels of phosphate and nitrogen. As a result, controlling the duckweed population becomes necessary beyond a certain point. Here are some strategies and suggestions for reducing the population of duckweed.
Duckweed is the tiniest flowering plant and is easily removed with nets. Floating boom, skimming, and raking are other methods that you can use. The sweeping of pond water is used in the floating boom method. Animals and human activities may bring the trash back to the pond, so place it far away from it. It is also suitable biomass for composting.
You can also use herbicides to destroy and remove duckweed. Duckweed can be controlled with products like Fluridone and Diquat. Remember that you should always use these items in the correct concentrations and follow the directions, warnings, and alerts on the package labels. You can also add chelated copper to the herbicides to make them more effective at killing duckweed.
Since duckweed tends to grow in still water, they can be controlled by aeration equipment, such as the bubble aeration device, which will cause the number of weeds to decline.
Blocking out the Light
Photosynthesis requires the presence of sunlight. Therefore, you can reduce the duckweed population by sheltering the pond areas with no sunlight reaching the pond waters. The pond’s southern side and region should be shaded to block as much light as possible.
Benefits of Duckweed in Aquarium (What is duckweed used for in fish tank?)
Filters Tank Water
High quantities of nitrates and phosphates can be produced by fish and other animals in the tank and dead leaves and plants, damaging their overall health. If you have duckweed in your aquarium, you may rest assured that the water will be free of toxins.
Duckweed can successfully ingest these harmful substances because it is an aquatic plant that thrives on nitrates and phosphates. It also absorbs ammonia and carbon dioxide, among other poisons.
Great Food Source
The nutritional profile of duckweed makes it an excellent food source for fish and other aquatic animals. This highly digestible plant has a protein content of about 40%, a fiber content of 25%, and a fat content of 5%. Its protein level is comparable to animal meat, making it an excellent protein source for your fish.
Duckweed serves as a complement to fish’s diet and provides something to munch on. Unfortunately, irregular feeding can spread diseases, which you can avoid by preserving duckweed.
It is a favorite food of most tiny fish. It is particularly popular with mosquito fish, tilapia, grass carp, goldfish, cichlids, and koi fish.
It’s also an excellent laxative. You can use it to keep goldfish moving by cleaning their intestines. It’s a low-cost food source because it proliferates and requires little upkeep.
Controls the Spread of Algae
For most aquarists, algae growth is a thorny issue. It’s an eyesore in the tank, lowering the aquarium’s aesthetic quality. Duckweed is an excellent aquarium plant for controlling algae growth. It conceals light by forming a lush green mat on the water’s surface. It also consumes all of the nutrients required for algae to develop. Not only does it prevents algae growth, but it also hinders the growth of any rooted plants.
Keep an eye out for dead algae in your fish tank if you have duckweed. By creating germs, the dead parts might degrade the water quality in your aquarium.
If you wish to keep additional plants in your tank, prune the duckweed regularly to allow light to reach the bottom.
Provides Cover and Protection
During the day, fish and water plants require protection from the sun. This is because their colors and abilities can be affected by controlled light. Like other floating plants, duckweed can provide shade for various aquarium fish.
Fish that prefer deep shadow, such as betta fish, benefit significantly from having duckweed in the tank. Duckweed decreases stress in the aquarium by providing a comfy resting and hiding area for the fish. In addition, it can filter extra light while also providing the ideal shade for the fish to relax and even lay eggs.
Another advantage of duckweed as a cover is that it helps reduce water surface evaporation, particularly beneficial in hot and dry seasons and locations. In addition, it can limit the amount of open water by covering the surface, blocking surface light, and lowering the temperature.
It can also be used as a tank lid to keep certain fish from jumping out. These fish mistake the water’s surface cover for a thick top, making them less likely to flee.
Aerates the Tank
Because it circulates air and creates oxygen, duckweed is an excellent source of oxygen for your fish tank. As a result, your tank will be secure from toxins, and your fish will be able to breathe easier. In addition, it improves water quality by absorbing CO2 from the water column and creating oxygen.
Even if your tank isn’t moving, you may check for adequate oxygen levels. On the other hand, dead duckweed consumes oxygen as it decomposes, so keep an eye out for dead plants and remove them from the water as soon as possible to avoid oxygen depletion.
Duckweed is known for swiftly absorbing nutrients and regulating algae-infested aquariums or ponds. However, the growth rate of duckweed can quickly become unmanageable, and most hobbyists do not want to deal with clusters of this plant later on.
It is a multipurpose plant that is a wonderful choice for people who’s just started aquaculture because it is a floating plant that does not require a special substrate to develop and reproduce. This plant is low-maintenance and requires just the most basic care, which mostly consists of providing fertilizers and reducing plant bulk to avoid entirely clouding the water surface.
Duckweed checks all the boxes if you’re looking for a compact, fast-growing, and low-maintenance plant. Have you tried growing duckweed in your aquarium? How did it go?