duckweed good for something?

[Mschmidt]

I was curious the other day and threw in some duckweed fresh from one another tank and dropped it in the reef. Everyone went nuts! Like everyone!

So I'm here to ask, are there any health risks from duckweed snacks?

Gif of a feeding:

 

[Nemo&Friends]

I do not know, but I often would like to give some of the green algae from my pond to my rabbit fish. I have not dared yet. But if your fish are doing well with duck weed, I will try.

 

[stoney7713]

I don't see how it would hurt, a lot of fresh water fish eat duckweed.

The only thing I can think of is how it was grown, ferts and such. Still though a lot macro algaes and phytoplankton is grown with them and we feed those to our fish and tanks.

 

[Mschmidt]

I do not know, but I often would like to give some of the green algae from my pond to my rabbit fish. I have not dared yet. But if your fish are doing well with duck weed, I will try.

The whole tank exploded with activity for it. Even the firefish was aggressively feeding on it! I tried algae from salt to fresh for my angels and that gave me an outbreak. worth a shot though. Cheap food if they take it.

I don't see how it would hurt, a lot of fresh water fish eat duckweed.

unfortunately none of mine.

The only thing I can think of is how it was grown, ferts and such. Still though a lot macro algaes and phytoplankton is grown with them and we feed those to our fish and tanks.

just betta poo. ferts shouldn't be an isssue after the greens take the nutrients in would it?

 

[stoney7713]

The whole tank exploded with activity for it. Even the firefish was aggressively feeding on it! I tried algae from salt to fresh for my angels and that gave me an outbreak. worth a shot though. Cheap food if they take it.


unfortunately none of mine.

just betta poo. ferts shouldn't be an isssue after the greens take the nutrients in would it?

Yeah I've got a ton of duckweed and only my koi, goldfish, and turtles eat it. But that's not the tank that is overwhelmed with it!

Personally no, I don't think there's an issue with ferts. Some people on here make a big deal of it though.

 

[Mschmidt]

Yeah I've got a ton of duckweed and only my koi, goldfish, and turtles eat it. But that's not the tank that is overwhelmed with it!

Personally no, I don't think there's an issue with ferts. Some people on here make a big deal of it though.

I wish I had fish that ate it. Guess I'll just keep dumping it in the reef.

 

[EricR]

Interesting idea.
I have a friend who's into hydroponics and she has tons of duckweed that she does all kinds of stuff with. (I never thought about trying it as food for marine herbivores -- might have to give it a whirl)

No point to my post -- just yappin'

 

[Stoneyed]

As an occasional treat, it should be fine (especially for herbivores). Duckweeds have a lot of vitamins, minerals, omega 3's, and are a good, complete source of protein. They also act like mineral "magnets," soaking up divalent cations (like Mg) up to ~10% of the plant's dry mass. Wolffia would probably also be a great addition, with a nearly identical nutritional profile, but smaller size for smaller mouths.

Downside, is duckweeds also produce oxalic acid / calcium oxalate (like kale or spinach). This can cause kidney stones in humans that are sensitive, and has caused ill effects on salmon feeding trials (carnivore). Tilapia and white shrimp, on the other hand, perform well on high inclusion rates of duckweed in their feed. There is a relation between oxalic content and Ca in the growth media, so softer water would be less risky.

I'm a bit of an expert in duckweed, so i'll answer whatever I can that doesn't involve IP or trade secrets.

 

[stoney7713]

As an occasional treat, it should be fine (especially for herbivores). Duckweeds have a lot of vitamins, minerals, omega 3's, and are a good, complete source of protein. They also act like mineral "magnets," soaking up divalent cations (like Mg) up to ~10% of the plant's dry mass. Wolffia would probably also be a great addition, with a nearly identical nutritional profile, but smaller size for smaller mouths.

Downside, is duckweeds also produce oxalic acid / calcium oxalate (like kale or spinach). This can cause kidney stones in humans that are sensitive, and has caused ill effects on salmon feeding trials (carnivore). Tilapia and white shrimp, on the other hand, perform well on high inclusion rates of duckweed in their feed. There is a relation between oxalic content and Ca in the growth media, so softer water would be less risky.

I'm a bit of an expert in duckweed, so i'll answer whatever I can that doesn't involve IP or trade secrets.

Trade secrets on Duckweed? Now I've heard it all! The bane of planted tanks!

No, thank you for the pro information it's definitely helpful!

 

[EricR]

As an occasional treat, it should be fine (especially for herbivores). Duckweeds have a lot of vitamins, minerals, omega 3's, and are a good, complete source of protein. They also act like mineral "magnets," soaking up divalent cations (like Mg) up to ~10% of the plant's dry mass. Wolffia would probably also be a great addition, with a nearly identical nutritional profile, but smaller size for smaller mouths.

Downside, is duckweeds also produce oxalic acid / calcium oxalate (like kale or spinach). This can cause kidney stones in humans that are sensitive, and has caused ill effects on salmon feeding trials (carnivore). Tilapia and white shrimp, on the other hand, perform well on high inclusion rates of duckweed in their feed. There is a relation between oxalic content and Ca in the growth media, so softer water would be less risky.

I'm a bit of an expert in duckweed, so i'll answer whatever I can that doesn't involve IP or trade secrets.

I'm inferring from your post that you, personally, wouldn't recommend it as a staple for marine herbivores (due to what you said in your 2nd paragraph).
Is that correct?

 

[Mschmidt]

Interesting idea.
I have a friend who's into hydroponics and she has tons of duckweed that she does all kinds of stuff with. (I never thought about trying it as food for marine herbivores -- might have to give it a whirl)

No point to my post -- just yappin'

Thanks for coming by!

As an occasional treat, it should be fine (especially for herbivores). Duckweeds have a lot of vitamins, minerals, omega 3's, and are a good, complete source of protein. They also act like mineral "magnets," soaking up divalent cations (1) (like Mg) up to ~10% of the plant's dry mass. Wolffia would probably also be a great addition, with a nearly identical nutritional profile, but smaller size for smaller mouths.

Downside, is duckweeds also produce oxalic acid / calcium oxalate (like kale or spinach). This can cause kidney stones in humans that are sensitive, and has caused ill effects on salmon feeding trials (2) (carnivore). Tilapia and white shrimp, on the other hand, perform well on high inclusion rates of duckweed in their feed. There is a relation between oxalic content and Ca in the growth media, so softer water would be less risky.

I'm a bit of an expert in duckweed, so i'll answer whatever I can that doesn't involve IP or trade secrets.

Am I glad you stepped in! Thank you for this. Does (1) mean they would drop Mg in the reef? or is it limited to an environment it can live in? and (2) would indicate slight danger for the carnivores in the tank?

Wolffia seems even more burdensome in a home aquarium than the duckweed. as convenient as it would be to eat.

 

[Stoneyed]

Trade secrets on Duckweed? Now I've heard it all! The bane of planted tanks!

No, thank you for the pro information it's definitely helpful!

Yeah, i work for a company that grows/processes it for food ingredients. We have a ton of IP on nutrition, crop management, and processing. Duckweed (and derived protein and fiber products) are GRAS (Generally Recognized As Safe) by the FDA.

I wouldn't use it as a staple food without some decent testing on long-term effects. May not be an issue, but i would err on the side of caution. As an occasional treat, it should be fine.

You can also grind it up, strain out the fiber, and add some acid to precipitate the protein. Strain the protein curds out, and dry them to make a protein concentrate. Very similar to making cheese, and reduces the oxalic acid significantly. I use something similar as a coral food.

 

[Stoneyed]

Thanks for coming by!


Am I glad you stepped in! Thank you for this. Does (1) mean they would drop Mg in the reef? or is it limited to an environment it can live in? and (2) would indicate slight danger for the carnivores in the tank?

Wolffia seems even more burdensome in a home aquarium than the duckweed. as convenient as it would be to eat.

If you got slick with the growth media for the duckweed, then yes it *could* be used as a targeted mineral source. Keep in mind that it's bound to the plant, so it would only be released as fish waste.

It won't hurt carnivores, but i wouldn't target feed it to them... at least not in large quantities.

Wolffia may be easier to do in a fishbowl than a small tank. it gets everywhere, and is less "floaty" than it's larger cousins.

 

[Mschmidt]

Yeah, i work for a company that grows/processes it for food ingredients. We have a ton of IP on nutrition, crop management, and processing. Duckweed (and derived protein and fiber products) are GRAS (Generally Recognized As Safe) by the FDA.

I wouldn't use it as a staple food without some decent testing on long-term effects. May not be an issue, but i would err on the side of caution. As an occasional treat, it should be fine.

You can also grind it up, strain out the fiber, and add some acid to precipitate the protein. Strain the protein curds out, and dry them to make a protein concentrate. Very similar to making cheese, and reduces the oxalic acid significantly. I use something similar as a coral food.

So I process it next time I make diy frozen food.

 

[Stoneyed]

So I process it next time I make diy frozen food.

Or blanch it. Blanching (~ 1 minute) followed by immediate cooling will also significantly reduce oxalate.

 

[Mschmidt]

If you got slick with the growth media for the duckweed, then yes it *could* be used as a targeted mineral source. Keep in mind that it's bound to the plant, so it would only be released as fish waste.

sounds like a lot of work.

It won't hurt carnivores, but i wouldn't target feed it to them... at least not in large quantities.

It's usually a scatter feeding. I think that is part of the fun for the tank. ignites their hunting drive.

 

[Stoneyed]

sounds like a lot of work.

It's usually a scatter feeding. I think that is part of the fun for the tank. ignites their hunting drive.

blanch + freeze any extra duckweed harvest. bonus points if you thaw it in selco.

 

[EricR]

blanch + freeze any extra duckweed harvest. bonus points if you thaw it in selco.

Do I get bonus points for knowing what Selcon is but not what "blanch" means?

 

[MoshJosh]

I watched a video once about a freshwater fish farm that had oodles of duckweed. Apparently the mechanism it uses to float is different than other floating plants? Many floating plants have a sort of air "bladder" where as duck weed is buoyant due to some sort of oil it produces? The fish farm was looking into if the oil could be removed and used as a bio fuel. . .

This was just some rando youtube video so who knows. . . maybe @Randy Holmes-Farley could tell us???

Also, goldfish love eating duck weed so there's that

 

[Stoneyed]

Do I get bonus points for knowing what Selcon is but not what "blanch" means?

Yep!

Blanching is simply dumping it in boiling water for a short time (dependent on what you are blanching... in this case ~1 minute), then rapidly cooling. It stops enzyme activity, as well as leaching out oxalic acid.