The Benefits of Growing Duckweed

Growing Duckweed

Growing Duckweed
Growing Duckweed | Source

Duckweed Growth

For some duckweed is a menace, for others it's a Godsend. This plant has the ability to reproduce rapidly, it can double in just 16 hours - 2 days, depending on its growing environment.

This makes it either a formidable enemy or a fantastic ally.

Today I would like to highlight the positive side of duckweed and tell you why we have built specially designed ponds to grow this here on our farm in Brazil.

For those of you who don't know what duckweed is, it is a small floating plant that grows on still ponds. It can cover an area rapidly and because of this can cause problems. Now however, duckweed is being touted as a miracle plant for many reasons including the ones listed below.

  • Cost effective renewable energy.
  • Water filter
  • Mosquito prevention
  • Prevents algae growth
  • Reduces evaporation on bodies of water
  • Virtually free animal feed
  • Food for humans

Duckweed as a Water Filter

Duckweed loves muck. It can clean the water from farms which are rearing cows, hogs, chickens etc. The run-off from these farms can cause an ecological nightmare if left untreated and allowed to leech down into the water table. Duckweed can clean this water by absorbing the resulting chemicals.

In Palestine, they are looking at using duckweed to clean their water systems as they have very limited fresh water available. If you would like to read more about their plans for duckweed, I have a link at the bottom of the page.

Our duckweed ponds
Our duckweed ponds | Source

Control of Mosquitoes

Mosquitoes love shallow still pools of water to lay their eggs in. This is a major problem in many countries, not just third world countries. Duckweed could be the solution.

Because duckweed covers the surface like a thick blanket, it blocks the mosquito from laying eggs. Malaria and dengue fever are two of the diseases spread by mosquitoes here in Brazil and other parts of the world.

Stop mosquitoes breeding and you drastically reduce the number of illnesses and deaths attributed to them.

Duckweed as a Bio-Fuel

Scientist are working on ways to utilize duckweed as a bio-fuel. With the rapid reproduction of this plant, it has not only the scientists but also the environmentalists taking notice.

Other plants are being grown for bio-fuel but none grow with the rapidity of duckweed. Currently the main bio-fuel crops are corn (maize), elephant grass, and sugar cane. These take up vast swathes of farmland, often in third world countries, which could be used to grow food crops for the local population instead of crops which will be made into bio-fuel.

The advantage of duckweed is not just its speed of growth but because it grows on water, it frees up the land for farming food crops. Plus with its water purifying properties, it leaves clean water behind.

Duckweed as Tilapia Food

The reason we decided to grow duckweed is to feed our tilapia. We have a small farm here in northern Brazil where we raise tilapia for the local market.

We are growing the duckweed to use as a supplemental feed for the fish. The high protein content of it makes this an ideal food for them. Although we feed them this astounding plant, this alone will not sustain the fish. We still feed them pellet food every other day as this ensures all the nutritional requirements of the fish are met. Feeding the fish duckweed has reduced our feeding bill by half!

A massive savings when you are feeding several thousand fish.

It isn't just fish that eat duckweed though. When fed to, chickens they produce more white meat. Thus commanding a higher price on the market.

In some parts of the Far East, it is being sold and consumed by humans as well.

How to Build Ponds for Duckweed

For our five ponds, we hired a digger and driver. Depending on how many you are wanting to construct, you may be able to do this manually. You will want the water to be no deeper than a foot. We made our ponds 30 m long by 2 m wide (98' x 6.5') and used a plastic liner in them.

Constructing our duckweed ponds
Constructing our duckweed ponds | Source

Choosing a Pond Liner

All pond liners are not created equally. For ours we needed one which was suitable to be used whilst underwater, in the sun, and one which wouldn't leach anything into the water which could damage the plants and subsequently cause problems with the fish.

Here in Brazil, the UV light from the sun is in the extreme category. This coupled with the salt in the air tends to destroy fabric, plastics, metals etc. Environmental elements need to be considered when selecting a liner.

Remember, when you calculate the dimensions, you need to leave enough for the ends and the sides.

Once you have laid this in your shallow pond, secure it whilst you fill it with water. We went low tech and used bricks to hold it down from the constant wind we have here.

Getting Your Duckweed to Grow

Your duckweed pond will require feeding. This is done with manure which has been soaked in water. We use a large plastic trash can for this purpose.

My husband puts the manure in, (we use chicken) and then fills the trash can with water to allow it to soften. Then he buckets this mixture into the ponds. Onlookers should stand well back as there will be splashes. You will know in a couple of days if you have the mixture correct because you will have a rapid growth of duckweed.

If the roots are long, more than a couple of inches, you need more manure. The roots are trying to stretch out and find nourishment. This is why the ponds are kept shallow.

Harvesting Duckweed

Harvesting the duckweed is easy. We simply use a swimming pool net on an extendable aluminum pole. This is a quick and efficient way to scoop it out. The weight of the water laden duckweed can be heavy. I found it beneficial to walk to where I want to scoop from, scoop it out and allow the water to drain off back into your pond. You don't need to be introducing any manure into wherever you are moving your duckweed to. The further away you are using your net, the heavier the duckweed will feel. Move closer to where you are working from and save your back.

This is also a good way to remove any leaves which may have blown in. If you live where there are trees, it is a good idea to put up a barrier such as chicken wire or plastic fencing to keep as many leaves out as possible.

Always clean your net afterwards to prevent any bits of duckweed from dying on the net and causing a blockage.

Inexpensive overflow system
Inexpensive overflow system | Source

Overflow for Ponds

My husband made an overflow system out of plastic pipe and Coke bottles. We can get downpours that last several hours and deposit an enormous amount of water in a short time.

Because duckweed floats, we needed something to allow the water to flow out but not carry the duckweed with it. This is a simple but effect method.

Also be aware, after a heavy rainstorm you may need to add more manure, as the fresh water will have diluted your ponds.

Wildlife in the Ponds

Many a night, during the mating season, we have many frogs in the duckweed ponds. We encourage everything here with the exception of cane toads.

There are beetles and other aquatic life which have made their way into the ponds on the feet of herons. It is always a good idea to inspect the pond for things living in there, quality of the water and the condition of the liner. This can be done as a matter of course when you are harvesting your duckweed.

Cleaning the Pond

If you are using manure from a chicken farm, you may end up with sawdust debris in the bottom of your pond.It is a good idea to drain it occasionally to clean it.

This can either be done through evaporation, by siphoning off through a hose, or by using a bilge pump. If you have never siphoned off anything it is simple. Just get a length of hose, put one end of hose in your pond and place the other end at a lower level in the garden for example. Suck on the opposite end of the hose until water begins to flow.Remember you have added a lot of manure to the water so you don't want to drink this.

**If you only have one pond dedicated to your duckweed, keep some of your plant alive to use as a starter. This can be done in a jar of room temperature water.

Comments 56 comments

Blond Logic profile image

Blond Logic 6 weeks ago from Brazil Author


Pelo que tenho pesquisado, os níveis de proteína são os mesmos. Se usarmos feijão como um exemplo, que retêm os seus níveis de proteína. Eu acredito que isso seja verdade com lentilha de água.

ola 6 weeks ago

e verdade se vce secar o duckweed ele mantem a proteina

Blond Logic profile image

Blond Logic 5 months ago from Brazil Author

Hi Lee,

Thank you for that link it is very interesting and will be beneficial to the readers wanting more information.

Duckweed has many uses such as bio-fuels, human and animal food and as a water cleaner.

Now, when all the world is concerned about mosquitoes and the possibility for them to transmit the Zika virus, perhaps the time is right for city councils to take a fresh look at using this natural deterrent in lieu of spraying chemicals. Or at least to use in conjunction with spraying. So often the answers to many problems, are right under our noses.

Thanks for reading and that link.

Lee Sutter profile image

Lee Sutter 5 months ago

Thank you. This is the only site I could find that talks about duckweed to control mosquitoes. I've noticed for many years that I never have mosquito larva in the half wine cask containing my small goldfish, where I once added a teaspoon of duckweed from a local waterway near a California coastal estuary. I truly believe this tiny plant can solve many of the major man-made problems on our planet. Here is a very encouraging report from Feb. 2014, the Joint Genome Institute (JGI) of the United States Department of Energy

Blond Logic profile image

Blond Logic 15 months ago from Brazil Author

Hi Deb,

It is an amazing plant. We are now using it as a fertilizer on our 400 young coconut trees.

My husband is the photographer in the family and loves photographing the birds, and snakes here. Although we have had snakes in our lakes, never a water moccasin (thank goodness).

Thank you for your visit.

aviannovice profile image

aviannovice 15 months ago from Stillwater, OK

I'm impressed. I always wanted to know more about duckweed. We get a little on Boomer Lake, but it usually doesn't grow. We had a lot of rain over the spring and last month, so it helped it grow, I am assuming. I have seen other ponds and swamps, in the deeper South, where it grows like wildfire. As a matter of fact, I got a few shots of water moccasins in a swamp in a NWR covered with the stuff. Thanks for the great info.

Blond Logic profile image

Blond Logic 17 months ago from Brazil Author

You're very welcome, I am pleased you enjoyed it.

hi 17 months ago

thanks this is very cool

Blond Logic profile image

Blond Logic 19 months ago from Brazil Author

Hi Poetryman,

Normally when I try to recycle trash, I end up with ...different trash. Duckweed however is different.

I will be watching the news for when you do find a solution to save the world. I will say, "I knew him before he became famous."

Thanks for reading and the vote.

Blond Logic profile image

Blond Logic 19 months ago from Brazil Author

Hi Patricia,

Thank you for your kind words, vote and sharing. I hope you are having a wonderful day up there in Florida.

poetryman6969 profile image

poetryman6969 19 months ago

I hope that one day soon we will find a use for every seemingly useless thing. Politicians, lawyers, reality television, duckweed, kudzu, acorns, fire ants. One of my secret plans to save the entire world in spite of itself is take ALL of our trash and turn it into treasure. Not some make work, feel, good, paperwork shuffle but a real industry that turns trash into Bill Gates level billions.

Duckweed fills the bill. Voted up.

My secondary plan to save the world involves eating zombies. But we would have to find some zombies first.

pstraubie48 profile image

pstraubie48 19 months ago from sunny Florida

This is quite helpful information for someone who needs this kind of plant. I am going to be living where I cannot have something like this. Maybe one day when I have a large area I will create a duckweed pond Great instructions.

Voted up++++ and shared

Angels are on the way to you this afternoon ps

Blond Logic profile image

Blond Logic 2 years ago from Brazil Author

We used it specifically for our fish to eat. However it has so many uses. In areas where mosquitoes are a problem at certain times of the year, it is beneficial to have this.

Thanks for the votes and sharing.

Shyron E Shenko profile image

Shyron E Shenko 2 years ago

I had not heard of this before, this is fascinating. I like the idea that it can be used as a preventative for mosquitoes, though it would seem it that if it prevents mosquitoes from laying their eggs, it would prevent oxygen from getting into the water.

Voted up UAI, and sharing

Blessings to you my friend


Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

Yes it is simple, remember shallow still water is best. If the roots are long, there isn't enough food for it to grow. They like mucky water with fertilizer in it.

Good luck with it.

LauraVerderber profile image

LauraVerderber 3 years ago from Mobile, AL

I finally got some duckweed growing regularly in my fish tank! Now to get it growing enough that I can use it to supplement food for my gold fish. It was all a matter of getting enough circulation to keep the tank clean and having the water be still enough that the duckweed would survive. What I did was have hornwort floating on top, and that's what prevented the duckweed from getting sucked in the filter. I want to try growing it outdoors next. I heard it is very simple.

Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

Hi Moonlake,

I enjoy looking at it also. Thank you for your vote and sharing.

moonlake profile image

moonlake 3 years ago from America

I love the way duckweed looks on a pond. Goldfish like to eat it. Voted up and shared.

DonnaCSmith profile image

DonnaCSmith 3 years ago from Central North Carolina

Thanks for the info. Glad we don't have those critters here. Got plenty of folks dumb enough to lick them though!

Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

Hi Donna,

The cane toad produces venom through its skin. Nothing, that I know of, will eat them if they do they will die from the poison or become very ill. Here they are in plague numbers. Australia too has a horrendous problem with them. That said some people lick them to get high. It produces hallucinations.

DonnaCSmith profile image

DonnaCSmith 3 years ago from Central North Carolina

Very interesting Hub. I have a question - what is a cane toad and why do you not want them in the pond?

Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

Hi Letitia,

Glad you found it useful. Thanks for stopping by.

Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

Thanks Laura.

Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

Hi Jrueff,

Yes, it may well be all over the place. If you can't find it, it is cheap to buy off Ebay. There is a link to it in the page.

Good luck to you and your 'mini homestead'.

jrueff profile image

jrueff 3 years ago from Kansas City

Wow, now I'm going to have to introduce duckweed to my mini homestead - this may be a dumb question, but where do I find the duckweed to get started?

I'm guessing it's probably all over the place and I just haven't seen it around, but I'm not sure.

Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

I couldn't agree more. If you can't beat them, eat them.

LauraVerderber profile image

LauraVerderber 3 years ago from Mobile, AL

No problem. I really enjoyed your hub. It amazes me that people always complain about prolific plants like duckweed, water hyacinth, dandelions, etc., as enemy weeds when all I see are prolific food producers. It's just a matter of educating yourself and finding a way to use the plant in a productive way.

Blond Logic profile image

Blond Logic 3 years ago from Brazil Author

Hello Laura,

I find it amazing how fast that plant can grow. It makes you realize just how productive Mother Nature can be if we give her the chance. Thanks for stopping by.

LauraVerderber profile image

LauraVerderber 3 years ago from Mobile, AL

I grow duckweed to feed the fish in my pond too! Great article. :)

LetitiaFT profile image

LetitiaFT 4 years ago from Paris via California

I guess I got the tilapia backward. Thanks for clearing that up (no pun intended). I didn't realize the young fish ate algae. Your explanation helps me to understand why it's considered so important for developping economies. Thanks!

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hello Letitia,

I am not sure what you mean about the tilapia making the water muddy. They do make depressions in the sand and also they can survive in very low water. Here on our farm we have sand at that base of our lakes. Our lakes are governed by the water table and rise and fall as the rains come and go. Tilapia do clean algae out of the water and in some states in America, municipalities are using them to help clean the water. Young tilapia can survive by eating algae and this is one way tilapia farmers save on the food bill.

Our duckweed is grown in separate shallow ponds and scooped out to feed the fish. If left to grow uncontrolled, it will quickly spread.

Thanks for leaving a comment.

LetitiaFT profile image

LetitiaFT 4 years ago from Paris via California

Oh gawd, those no-see-ums. We had them in French Guiana when I worked there on sea turtles. There they're called nya-nyas, short for rien-rien or nothing-nothings. Nasty little buggers. But here in Paris near the Seine we have mosquitoes, amazingly enough. I wish I could grow duckweed in my potted plants!

Your article is fascinating. I've always loved duckweed for its aesthetic qualities, but I had no idea of its other uses. I seem to recall that Talapia can muddy clear water (though not as much as carp). Is that so and do you grow duckweed directly on their ponds to help clean them?

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hi Teaches12345,

When I was in Florida, it wasn't so much the mosquitoes as those horrible no-see-ums! We have a similar one down here in Brazil.

Ah tropical life!

Thanks for the compliment.

teaches12345 profile image

teaches12345 4 years ago

You did an awesome job on covering this topic and made it so interesting to read. I have learned much. Anything that gets rid of mosquitoes is tops on my list. Too bad I can't grow it in m pool.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

This is an interesting point. One night my husband armed with a flashlight, called me outside. We went to the duckweed ponds and there were frogs, croaking, there necks billowing out with each croak. They were spawning in there and the next morning we had foam. The frogs have come and gone and will return to spawn again.

The problem we have here are cane toads. (I must write a hub about them). They are a problem here as they are in Australia. They excrete a poison that kills anything that predates them.

We do everything we can to encourage frogs to stay in our garden. Anything that eats bugs that might bite me, can stay.

Glad you like the article.

Thanks for the comment.

rbm profile image

rbm 4 years ago

Fascinating article! I had no idea duckweed grows so fast. We have a little pond in our garden where we keep tadpoles right now, and unfortunately the mosquito larvae love it too, been scooping them out periodically. I am now thinking that duckweed would work very well here, and the tadpoles would probably be pretty happy with it too, right?

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hello Bright Meadow,

I am glad you enjoyed it. I plan to write more about various plants here. Sometimes it is hard to decipher what is folklore and what is fact here. My neighbor swears his mother-in-law can cure fever by putting a root under the bed of the feverish person.

Thanks for the comment.

BrightMeadow profile image

BrightMeadow 4 years ago from a room of one's own

I heard about this plant on a television program but they did not go in depth. I'm glad you shared this. I would love to hear more about the uses of other plants that you are familiar with as you mentioned in one of the earlier comments. Thanks for sharing this info.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hi Brenda,

Thanks, I am glad you enjoyed it.

It isn't just about tropical plants, I recently read a hub from a new hubber about what plants grow well together. Interesting info.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hi Angela,

Thank you. It took me awhile but get around to writing it, but now I am glad I've done it. I am pleased you liked it.

Angela Brummer profile image

Angela Brummer 4 years ago from Lincoln, Nebraska

This is an amazing article. New information I have nerver heard of presented beautifuly!

joanveronica profile image

joanveronica 4 years ago from Concepcion, Chile

Hi, greetings from Concepcion, Chile! This is a great Hub, well in line with some of our school work in the rural areas, the drylands. It reminds me of our efforts with the school project for worms (I wrote a hub about this project, maybe you would like to check it out?) I wish you every luck with your enterprise in Brazil.

brenda12lynette profile image

brenda12lynette 4 years ago from Utah

Thanks for the great information Blond Logic! I love learning about the different properties of plants. Voted up!

kartika damon profile image

kartika damon 4 years ago from Fairfield, Iowa

Hi Blond Logic - yes the pharma industry is all about making the big money. Nature has a cure for so many (perhaps all) of our ills. Having that knowledge is so valuable - and it's good so many more people are recognizing this. You are so lucky to live where people are close to the land and understand the power of plants and strive to live in harmony with the ecosystem. :)

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

We have a spare bedroom, come visit! There is always work to do on the farm.LOL

I think that when we stop and look at how small communities deal with problems, we can learn much from them. Sometimes, in our search for bigger, better, faster we lose sight of what is simple and more effective.

I'm pleased you enjoyed the article. Thanks for the comment.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hi Kartika,

Where I live in Brazil, there are many people with local knowledge of plants. One we have in our garden, the locals use it if they have dandruff.

Once when my husband had an inflammation on his leg, my neighbor brought over a plant, chopped it up, and put this on his leg. By morning the inflammation was gone.

So often the western world would rather take a pill than use something herbal or natural. Luckily I think this is changing.

Thank you for your comment.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hi Natashalh,

There are different varieties of it but you may well have it there. Sometimes things can be right under our noses and we don't appreciate them.

Thanks for stopping by.

Have a great day.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hello Wilbart26,

Thank you. Remember if you plant it, you have to control it. That is why we have ours in separate ponds. Because it can double every 1-2 days, by 60 days it could cover 79 acres!

Let me know how it goes.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hello phdast7,

Yes, places in the far east, Latin America, and parts of Africa. I have seen some homes that have the manure running into a large cylinder for bio gas for cooking then into a duckweed pond and then into a pool where fish are. It is an amazing plant. Although some people in countries such as Vietnam eat it, I personally haven't. A morning duckweed smoothie? Watch this space.

Thanks for stopping by and also sharing it. Much appreciated.

Blond Logic profile image

Blond Logic 4 years ago from Brazil Author

Hello RTalloni,

We first discovered the benefits of duckweed after looking for ways to reduce the cost of raising our tilapia. There is much research going on in the far east and Latin America where they are trying to increase rearing fish for local populations as well as the export market.

Thanks for your comment.

Mr. Happy profile image

Mr. Happy 4 years ago from Toronto, Canada

"The reason we decided to grow duckweed is to feed our tilapia. We have a farm here in Northern Brazil where we raise tilapia for the local market." - I love Tilapia - I might have to visit to have some fresh! : )

I have heard about the many positive uses of duckweed not long ago. It makes me happy to find that we are re-learning how to use what Mother Earth gives us.

Great article - thank You for bringing this topic to the general discussion, here on Hubpages. Cheers!

P.S. Thank You to Mrs. Theresa (Phdast7) once again today for sharing another great article!

kartika damon profile image

kartika damon 4 years ago from Fairfield, Iowa

Thanks - great article. I'm always happy to learn more about the environment and the amazing potential plants have to heal people and the planet.

Natashalh profile image

Natashalh 4 years ago from Hawaii

So cool! I think we have duckweed growing at work. i always just thought it was some weird plant. I had no idea it was so useful! Thanks for putting this hub together.

Wilbart26 4 years ago

This is a very informative hub about duckweed, I never thought, duckweed is this helpful. Thanks for this, I might consider planting duckweed also... Very helpful... Keep it up!

phdast7 profile image

phdast7 4 years ago from Atlanta, Georgia

This is absolutely fascinating. I had no idea. What a marvelous way to do so many things. Do you know if this is being done in many locations, many countries? Terrific article! Sharing.

RTalloni profile image

RTalloni 4 years ago from the short journey

How interesting! You have done a wonderful job of explaining why as well as the way you are growing duckweed. I'm not surprised that it we would discover that it has many benefits, only that the news is not more well known.

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    Mary Wickison (Blond Logic)598 Followers
    145 Articles

    I live in Brazil and share my knowledge of local food, plants and traditions through my articles. Offering a slice of life from paradise.

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