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Melody
Nov 23rd 2007, 07:23 PM
There's a Center for Duckweed Research & Development... I wouldn't have guessed that.:twitcy:

I read a great article about the nutritional benefits of Duckweed. The information I had before suggested that it wasn't a particularly good source of nutrition, albeit a decent source of vegetable protein. Turns out that the nutritional value depends on the conditions the duckweed is grown in. In fact, "Duckweed grown on nutrient-rich water has a high concentration of trace minerals, K and P and pigments, particularly carotene and xanthophyll..."

It is also highly digestible, "Compared with most plants, duckweed leaves have little fibre (5% in dry matter of cultivated plants) as they do not need to support upright structures. Roots, however, appear to be more fibrous. As a result the plant has little or no indigestible material even for monogastric animals. This contrasts with many crops such as soya beans, rice, or maize, where approximately 50% of the biomass is in the form of high fibre, low digestibility residues."

What's more, the protein in Duckweed is special. Its a vegetable protein which closely resembles animal protein, making it highly digestible and easily utilized by fish at the bio level.

The conditions required to grow duckweed of maximum nutritional value are included in the article.

Duckweed - a potential high-protein feed resource for domestic animals and fish (http://www.fao.org/AG/aga/AGAP/FRG/FEEDback/lrrd/lrrd7/1/3.htm)
R A Leng, J H Stambolie and R Bell
Centre for Duckweed Research & Development University of New England Armidale, NSW 2351

I love finding university studies/articles. They are very informative and a reliable source of information. The lack of marketing hype & bias is refreshing to the nth degree.:smile:

grumpystiltskin
Nov 23rd 2007, 07:42 PM
Great article Melody
Ive only been keeping it one of my tanks because the ameca splendens seem to like eating it, oh its in one other tank because of fry, it makes good cover
But as we all know, if you get one piece in a tank by accident it multiplies so quickly, it can become a nuisance

Katalyst
Nov 23rd 2007, 07:43 PM
I've been putting cupfuls of it in my gel food, good to know. Thanks Melody!

Melody
Nov 23rd 2007, 08:02 PM
Cupfulls.... I can't grow it fast enough, the snails eat it as quickly as I can grow it. There's always a bit, but I never get overgrown with it. Most of my light levels aren't high either, so I'm sure that makes a difference. Since mine is slow growing, it wouldn't be as nutritious according to the article. Of course, now I want to buy a high-powered light to grow it faster :rolleyes: .

Katalyst
Nov 23rd 2007, 08:27 PM
Cupfulls.... I can't grow it fast enough, the snails eat it as quickly as I can grow it. There's always a bit, but I never get overgrown with it. Most of my light levels aren't high either, so I'm sure that makes a difference. Since mine is slow growing, it wouldn't be as nutritious according to the article. Of course, now I want to buy a high-powered light to grow it faster :rolleyes: .
I have a high powered light on my fry & shrimp tanks that are heavily planted...I had one or two pieces of rogue duckweed that arrived with Micks plants and now a month later its everywhere! My goldfish get it as a treat but they inhale it so it'd never grow in there. The killies love to weave in and out of it as well.

Melody
Nov 23rd 2007, 08:34 PM
Light it is then! It makes sense that the tank parameters would have to be right too. Duckweed uptakes so much from the water. I suppose that it wouldn't grow as fast if it wasn't getting most of what they recommend, so I'm guessing that fast growth could be a reasonably accurate indicator of nutrition content.

Sounds good on paper anyway. :laugh:

grumpystiltskin
Nov 23rd 2007, 08:39 PM
I had one or two pieces of rogue duckweed that arrived with Micks plants

Sorry i try to get it all off but its so hard :smile:
but it seems its not too much of a problem for you

Melody
Nov 23rd 2007, 08:41 PM
Great article Melody
Ive only been keeping it one of my tanks because the ameca splendens seem to like eating it, oh its in one other tank because of fry, it makes good cover
But as we all know, if you get one piece in a tank by accident it multiplies so quickly, it can become a nuisance

Ameca Splendens are good algae eaters too, so I'm not surprised that they appreciate the duckweed.:smile:

Pamelajo
Nov 23rd 2007, 09:08 PM
because the ameca splendens seem to like eating it

Good to know, hopefully the ones Mel is sending will eat some of mine.

Cupfulls.... I can't grow it fast enough, the snails eat it as quickly as I can grow it.
I do to and could have sent some with the fish had I known. I take a cupfuly every other week and add to the plant eating snail tank.

Melody
Nov 23rd 2007, 10:10 PM
It takes a special kind of hobbyist to fail at growing duckweed you know.:rolleyes: I'm hopeless...lol.

Splendens are one of the best algae eating fish I'm told. I don't know what kind they prefer though, seems algae is a matter of taste quite often.

blainep
Nov 23rd 2007, 10:16 PM
My Canas LOVE duckweed, it's like candy for them. :laugh:

Melody
Nov 24th 2007, 12:28 AM
Cana's eat styro...lol.

Katalyst
Nov 24th 2007, 12:41 AM
Cana's eat styro...lol.
And tupperware! :wideeyed:

CACAdmin
Nov 24th 2007, 02:17 AM
I used to have lots of duckweed but have almost none. The only factor which has changed is the increased number of Limia Tridens and Mollies in the tanks.... hmmmm.... wonder who is eating it?

PPulcher
Nov 24th 2007, 07:42 AM
It takes a special kind of hobbyist to fail at growing duckweed you know.:rolleyes: I'm hopeless...lol.


Duckweed does not grow well for me in tanks where I have lots of Najas. I suspect the najas out competes the duckweed, or there is some kind of allelopathic chemicals involved.

Wiedertäufer
Nov 24th 2007, 08:48 AM
I found my hornwort does the same thing. Can grow one or the other, but not both.

Melody
Nov 24th 2007, 11:33 AM
Duckweed does not grow well for me in tanks where I have lots of Najas. I suspect the najas out competes the duckweed, or there is some kind of allelopathic chemicals involved.

Good thinking!I never have much in any tank, with or without Najas, but with my light levels that doesn't surprise me. Both plants being fast growers in optimum conditions, it certainly may be competition... could be traced to one element though, which could be supplemented. Duckweed loves its minerals so maybe one of those is the ticket.

The only proven allelopathic effects that I know of in aquariums is attributed to Hornwort. I'm far from up on the plant info though.