How To Grow Duckweed In An Aquarium

Last Updated on November 9, 2021 by Marco C.

Many aquarium owners know that duckweed can help keep the water clean, which is why many wonder how to grow duckweed in an aquarium. This plant is sometimes treated as weeds and some consider it a nuisance, but it has its advantages. This plant can be of great service to your aquarium and it can serve as an aesthetic detail!

What Is The Duckweed Plant?

Duckweed is a common sight in virtually every body of water, but it’s most common with still bodies of water. That’s why you can likely see it in ponds and lakes!

This type of plant is what we know as a floating plant, as it floats on the surface. In wetlands and ponds, areas where it really thrives, duckweed can cover the whole body of water! The reason duckweed is useful for aquariums is because of its purifying action!

Duckweed is one of the strongest purifiers out there, which is why many aquarium owners grow duckweed in their aquariums. This plant grows at an impressive rate, and its fast action makes it very popular. On top of that, it also acts as a reductant for algae growth!

If you let your duckweed cover the surface of your aquarium completely, it’s going to cause oxygen deprivation. This, reduced lighting and increased nutrient uptake helps stop algae growth.

However, if not controlled well, duckweed can present a problem for your fish! Because it spreads so fast, duckweed can quickly lower the amount of sunlight and oxygen in the aquarium. This is clearly bad for the fish, which is why it’s important to control its growth.

What Is The Duckweed Plant

Learn more about: How Much Light Do Aquarium Plants Need?

Growing Duckweed In An Aquarium

The best part about growing duckweed in an aquarium is the simplicity behind it! Duckweed grows at a staggering rate, which means that you just need to find some and let it thrive.

It’s best to buy duckweed in a pet store – most pet stores have duckweed. This plant is a great companion for koi fish and goldfish. It will keep the aquarium clean while it will also provide a nutrient source for the fish.

For starters, you don’t need to worry about light and water. Duckweed doesn’t have a problem with hard or soft water, while it can also stand low and high lighting. The most important thing you need to worry about is the stillness of the water! Duckweed likes still water, not flowing water.

Regarding water temperature; you should keep it between 17 and 26 degrees Celsius.

However, it isn’t necessary to grow the duckweed in the same aquarium you keep your fish in! You can grow it in a separate environment before placing it with the fish!

It’s much easier to grow duckweed in enclosed aquariums than in open ponds. You can easily control the conditions of an aquarium, while you can’t do the same with a pond.

However, you need to know that duckweed is terribly difficult to remove once installed. Many owners find themselves lost for words once they remove duckweed, only to find it completely regrown a few days later. It really does take only a few days for duckweed to grow to immense sizes, so make sure that you can regulate its growth.

Duckweed Care

Given that duckweed grows like a weed, it’s incredibly simple to take care of it. You usually won’t have to make any adjustments – the only thing you should work in is making sure that your fishes can cohabitate the aquarium!

If you want to grow duckweed in great amounts, then you should grow it in an aquarium where you don’t keep fish! The best way to propagate growth is to provide the duckweed with high-quality lighting and spectrum minerals. Know that duckweed is especially vulnerable to any water movement. If you, however, keep the water still and maintain ideal conditions; duckweed will grow fantastically fast.

When you’re growing duckweed in the same aquarium with your fish, there are a few things you need to be careful about. For example, duckweed can cause problems with your electronics. It’s not at all uncommon for duckweed to get tangled up with the water filter. To avoid this, place the filter a few inches below the surface or keep your duckweed in a restricted area.

Control your duckweed’s growth with the simplest method – scoop out the excess. 

Fish, Algae, and Duckweed In The Same Aquarium

Not all fishes can live in the same habitat as duckweed. That’s why it’s important that you know in advance whether your fish can share the tank with duckweed.

Carnivorous fish, for example, won’t eat duckweed but will use it for shade and as a hiding spot. Some species like the koi fish and the goldfish will eat the duckweed. This is, however, good for two reasons. Firstly, duckweed is a good source of nutrients and it’s keeping the fish satiated. Secondly, the fish are actually helping you in controlling the growth of the duckweed!

Another plant that may come in direct conflict with duckweed are algae. Since duckweed is very effective in fighting algae, it’s likely that your algae population will be kept to a minimum. This is especially important if you’re planning on keeping an aquarium with plants and algae only. Algae and duckweed can’t cohabitate and you shouldn’t place them in the same environment.

There are also things you need to watch out for! Despite being useful for the most part, duckweed can cause problems if you don’t control it. If it manages to cover the whole surface of the aquarium, it will limit oxygen and light supply to the fish. This is something you definitely want to avoid!

Additionally, if you have plants that depend on nutrients drawn from the water, you should be careful with duckweed. Duckweed will affect the number of those nutrients in a negative way. This is why duckweed works well with plants that draw their nutrients from the substrate, instead of the water.

In Conclusion

If used and maintained properly, duckweed can be a great companion for cleaning your aquarium. It can also be a great source of food for your fish. However, you have to take good care of the plant, as it will take over the aquarium and start causing trouble if you don’t!

Read more about: Your Perfect Guide To Finding The Most Realistic Artificial Aquarium Plants

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