Getting Rid of Duckweed

[nerdelish]

So about 2 months ago I bought some blue velvet shrimp online. When I got the shrimp there was duckweed in the water with them. I tried to add the shrimp to the tank without adding duckweed but one or two (or five) must have snuck into the 29 gallon.

Now my tank is overrun with it and I don't like how it looks. It wouldn't be so bad if it stayed on the top of the water but it gets pushed around the body of my tank by the filter flow and I don't like the look of it.

Is there an easy way to get rid of it or am I stuck netting it for hours and hoping I get it all?

P.S. I have frogbit in the tank and I like it.

 

[TheresaM]

Ugh, not sure if there's any way to get rid of it other than manually. I had issues with it in my Endlers tank, started posting about it here. Long story short, I got a floating plant guard to corral off a reasonable portion then netted out anything outside of that area. It still multiplies but at least it's contained.

 

[nerdelish]

Ugh I was afraid of that. Are floating plant guards easy to find and relatively inexpensive? I may have to try that.

 

[TheresaM]

Some people DIY but I'm not that creative or handy, I ordered mine from Han Aquatics.

 

[nerdelish]

Thanks for the link. I will weigh DIY vs purchase and go from there.

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[TheresaM]

Thanks for the link. I will weigh DIY vs purchase and go from there.

His shipping costs are very reasonable; I order a lot of plants and almost all of my shrimp supplies from him.

 

[Laeris]

I bought one when I ordered ricciocarpus natans from Han. The only better option than his is an acrylic guard attached with silicone IMO. Use measuring tape, not a tape measure if you're measuring a curve, or a string on a ruler.

 

[FishFlow]

Do you do waterchangers? With your gravity suction vacuum, invert the tank end for a make shift skimmer. Suck out all the duckweed from the top.

First couple weeks will be duckweed heavy. But with weekly waterchanges, and pulling out the easily skimmable dw. It'll be a non-issue.

Or... Just EMBRACE the Duckweed!! It is your friend.

 

[wildroseofky]

Increase water flow at the surface of the tank. Duckweed doesn't like strong current. It takes a few weeks but it will all die out. Skim off as much as you can to make the process go quicker. You can make your plant corrals out of airline tubing and tubing connectors. Just make a circle and add a straight connector. If you want to anchor it in place use a three way connector and add a suction cup.

 

[nerdelish]

I bought one when I ordered ricciocarpus natans from Han. The only better option than his is an acrylic guard attached with silicone IMO. Use measuring tape, not a tape measure if you're measuring a curve, or a string on a ruler.

Thanks! I don't have a measuring tape so the string suggestion was a good one.

 

[nerdelish]

Do you do waterchangers? With your gravity suction vacuum, invert the tank end for a make shift skimmer. Suck out all the duckweed from the top.

First couple weeks will be duckweed heavy. But with weekly waterchanges, and pulling out the easily skimmable dw. It'll be a non-issue.

Or... Just EMBRACE the Duckweed!! It is your friend.

Yeah I do 50% each week. The make-shift skimmer is a good idea, but I do have shrimp that like to climb around on my floating plants so I am worried the suction might get them as well?

I have decided that I will put some duckweed in my 5 gallon betta tank. I have much less flow there and the roots of the frogbit are starting to get a little long for such a small tank.

 

[nerdelish]

Increase water flow at the surface of the tank. Duckweed doesn't like strong current. It takes a few weeks but it will all die out. Skim off as much as you can to make the process go quicker. You can make your plant corrals out of airline tubing and tubing connectors. Just make a circle and add a straight connector. If you want to anchor it in place use a three way connector and add a suction cup.

Thanks for the suggestion! That helps a lot!

 

[DaleV87]

Increase water flow at the surface of the tank. Duckweed doesn't like strong current. It takes a few weeks but it will all die out. Skim off as much as you can to make the process go quicker. You can make your plant corrals out of airline tubing and tubing connectors. Just make a circle and add a straight connector. If you want to anchor it in place use a three way connector and add a suction cup.

? Thanks for that advice. I like your corral ideas.


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[Fishperson]

The reason why it never dies is it gets sucked into the filter and spit back out, still kicking, days later. Just when I thought I got rid of mine I found 2 or 3 more. My filter is made of transparent plastic so I can see them in the filter media.

If you really want to be rid of them, I'd go crazy and clean everything out. Take all your floating plants out into a small bucket, then dip each frogbit into water to rid it of duckweed, and place it into another, "clean" bucket free of duckweed. Then, take your filter media out and clean it, removing as much as you can. Then, go around the hardscape with a tooth brush and brush any duckweed that's stuck in it out so it floats on the top, and net that out. Get a spray bottle and spray the stuff that's stuck to the sides so it falls down into the water and net that out.

Then pull out any stragglers for the next week or so.

I think once you get down to only one or two plants here or there, and you just keep pulling them out whenever you see them, they'll die eventually.

 

[ScotJudd]

Ridding your tank of duckweed is just like ridding your tank of pond snails, after the initial removal of all visible invaders it's a daily task.
See one, remove it. Don't give up and one day you'll realise that's there's none left.



Sent from my iPad in West Yorkshire, U.K.

 

[Atxpunx]

Growing Val species in the affected tank will eventually kill off duckweed. There's an allelopathy between vals and duckweed. Vals always win.


Cha boi Jessie.

 

[TheresaM]

Growing Val species in the affected tank will eventually kill off duckweed. There's an allelopathy between vals and duckweed. Vals always win.

This isn't the first time I've read this on the forum and my Endlers tank proves that doesn't always work. The tank is very heavily planted with vals only, even with the plant guard the duckweed multiplies like crazy.

 

[Brookster123]

I just started using it as a garnish on my pasta dishes.. Tastes a little off at first but you'll get used to it. Cept the time the rams horn snail got in too, chipped a tooth.. youch!

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[TheresaM]

I just started using it as a garnish on my pasta dishes.. Tastes a little off at first but you'll get used to it. Cept the time the rams horn snail got in too, chipped a tooth.. youch!

Hate when that happens!

 

[Fishperson]

After hearing about that val vs. duckweed thing I googled a bit and found this:

http://www.pjoes.com/pdf/20.5/Pol.J.Environ.Stud.Vol.20.No.5.1153-1159.pdf

Basically, it says that vallisneria spiralis releases allelopathic chemicals that help kill this blue green algae. I suppose it could also work on duckweed, but maybe not.

Anyway, they found that hydrilla releases these chemicals in much, much higher concentrations than vals do. 179 times more, in fact. So it could be worth a shot to grab some hydrilla if you can find it.