# Killing Duckweed with guppies



## J9e8r6m (Jul 27, 2006)

Here is the issue.

my ten gallon is infested with both duckwed and guppies.

I like the guppies, but now the duckweed so much. It covers the entire surfaces many plants thick, and entangles itself in the najas so it is impossible to kill. I have trapped the najas is a giant clump under a rock and the duckweed all floated to the top, but...

1. The duckweed cannot all be removed with your hands, as their is too much and it floats away and hides in my filter and..

2 If I use a net, the most retarded species of fish on the planet (guppies) swim into the net. As soon as the net hits the water I have between four and eight guppies in it immedeatly. It's a small net, and along with the jeuvenile fish, i've had 12 guppies cram into one net.

I thought seperating the najas from the duckweed would be hard, but how can I seperate the guppies from the net?

Does anyone have any suggestions on how to get duckweed out of a tank?


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## toofazt (Jun 18, 2005)

You can try placing a paper towel on top of the water and remove it. The duckweed might stick to it but the fish won't.


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## JenThePlantGeek (Mar 27, 2006)

Shopvac!!! - hehe. It is very satisfying to see the duckweed just disappear, but don't put it TOO far in the water or the guppies will get a rough ride!


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## A Hill (Jul 25, 2005)

maybe try to syfoon it out somehow?.... not too sure best of luck tho because ive heard its impossible to get rid of...


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## Canoe2Can (Oct 31, 2004)

I always just skim it off with a plastic cup. Every tank should have a plastic cup nearby. If you're careful, you can avoid catching guppies, or at least dump them back when you do. On the other hand, if the tank is infested with guppies, what's a few less? They'll make more after all.

I've never tried the paper towel method, but it might work. Oh, and Fish Newb is right, YOU WILL NEVER GET RID OF IT!


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## yoink (Apr 21, 2005)

Canoe2Can said:


> I always just skim it off with a plastic cup. Every tank should have a plastic cup nearby. If you're careful, you can avoid catching guppies, or at least dump them back when you do. On the other hand, if the tank is infested with guppies, what's a few less? They'll make more after all.


Same here. I use a small plastic cup and let the water trickle into it slowly. You won't get all the duckweed at once, It will be an ongoing battle for a bit. Doing this every few days should all but eradicate the duckweed.


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## Hoppy (Dec 24, 2005)

For reasons I don't understand, I seem to have gotten rid of my duckweed. All I did is scoop it out with a big net, having a rectangular opening. I would keep just the metal frame of the net in the water and push the mat of duck weed to the end, where it would tumble into the net. Whe I got down to just small patches I always had to dump the curious guppies out before taking away the duckweed. I did this for several months. Today I realized I haven't seen any duckweed for at least a month. The water may be warmer now than ever before, but other than that, and reducing the light period from 10 hours to 8- hours I don't think I did anything differently.


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## bigstick120 (May 23, 2005)

A net wroks great, every water change I just got as much as I could until I didnt have it anymore


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## Rod Hay (Feb 11, 2006)

OR...you could borrow someone's goldfish! I keep it growing in other tanks and a tub just to feed it to my goldfish (two shubunkin, one fantail, & one juvenile ryunkin). Whatever duckweed I put in is gone by the next day.

However the dumb goldfish wouldn't eat the guppy fry I dumped in and now I have two half inch guppy babies sharing their tank. I ended up removing several other fry to the diamond tetra/angelfish abode for population control.


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## Mori (Jul 23, 2003)

I scooped out my duckweed to feed to my goldfish...then one day I overscooped and it was gone. Many months later, I moved a few tubes and I am infested with duckweed again. The goldfish are delighted.

Borrowing goldfish would work if it were a bigger tank, but there's a chance they'd eat fry. I think mine would. They tend to do what you don't want them to do. (10-gallon tank sized goldfish wouldn't be able to make any headway against the duckweed--an experiment I'm running right now in a QT tank.)


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## 2wheelsx2 (Jan 27, 2006)

Increase surface agitation and get a few silver dollars for a week or two. I got an infestation which filled the entire surface of my 125 gallon (that's a 6 footer) and the 4 three inch SD's took care of it all in about 2 weeks. The surface agitation also appears to slow their multiplication rate.


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## 247Plants (May 10, 2006)

Well I can tell you heat wont get rid of it...my tank is in the upper 80's because of the heatwave and its getting thicker than ever before.....right now Im trying to float riccia and salvinia minima to maybe outcompete it but it seems to be a futile battle.....i guess a small victory is better than no victory right?

if you really want to get rid of it completely you are gonna have some casualties for sure......but i would rather have guppies reproducing in my tanks than duckweed but i think they reproduce at about the same rate right?(kidding on that last comment)


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## gbhil (Oct 28, 2005)

I'll second the Silver Dollar idea. 3 petco SD's picked a mess of duckweed out of some java moss I have floating in a breeder tank in just a few days.


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## J9e8r6m (Jul 27, 2006)

The hardest thing is that even when I seem to kill all the plants, they always came back. I blacked out my tank (Najas, java ferns and anubias never die even without a light ^.^) and the leaves on the duckweed just got smaller. I've cleaned off the surfaces before and it keeps coming back, I think the filter hides some of it. I'll have to try to put something in there that will eat it. Thanks ^^


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## mrbelvedere (Nov 15, 2005)

gbhil said:


> I'll second the Silver Dollar idea. 3 petco SD's picked a mess of duckweed out of some java moss I have floating in a breeder tank in just a few days.



What did you do with them later?


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## 2wheelsx2 (Jan 27, 2006)

Lots of LFS's will take back large silver dollars. They are pretty spectacular when they are large. In fact, I am considering taking mine back, now that they are taking up room that I could have for my cichlids.  Mine are currently 4.5 inches.


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## twychopen (Dec 17, 2008)

the SD's won't eat the other plants?


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## 2wheelsx2 (Jan 27, 2006)

They will. You just have to learn which ones they're less likely to eat. I have found that I cannot keep Cabomba and the more delicate types. Hardier, faster growing plants, like Jave Fern, Vals, Water Sprite, etc. don't suffer too much damage. If they grow slow, like Anubias, even with the tough leaves, some don't survive.


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## twychopen (Dec 17, 2008)

Rabbit trail...sorry..
I have comboba, I keep hearing its not hearty. I have had that stuff grow in cichlid tanks before! My Comboba grows right now about 3/4 to 1" a day per stem! I bought the plants two weeks ago about 6" tall. I just cut one that was over 2'6" and replanted it in a new tank...why is it listed as delicate? It seems like it would grow too fast for SD.


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## 2wheelsx2 (Jan 27, 2006)

twychopen said:


> Rabbit trail...sorry..
> I have comboba, I keep hearing its not hearty. I have had that stuff grow in cichlid tanks before! My Comboba grows right now about 3/4 to 1" a day per stem! I bought the plants two weeks ago about 6" tall. I just cut one that was over 2'6" and replanted it in a new tank...why is it listed as delicate? It seems like it would grow too fast for SD.


My 4 SD's mowed the Cabomba to nothing but stubs in a week. Doesn't how fast they grow when the SD's go at it non-stop.


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