I have this weed taking over my tank. How do I get rid of it?

Look like yellow water primrose. Genus is Ludwigia. I had a small pond with this stuff and just pulled it out manually.

Here is excellent source of information http://aquaplant.tamu.edu/management-options/water-primrose/

Heard cornmeal works on algae, never tried it though.

Those just showed up in our pond as well. I'm waiting for the mill weed and duck weed to explode again like last year.

good morning,

there is a guy in louisiana that goes all over..........does pond management( non toxic).....don't remember the name of the company...he advertises on the radio....you might put pond management in your search engine,,,,,,,

if i hear the ad again, i will post it...

good luck,
PURA VIDA,
bluebonnet2

I can't tell from the pic but not real sure that's primrose. Could be several types as Well.
I'm fixing to kill primrose in one of my tanks. Here's the link http://aquaplant.tamu.edu/management-options/water-primrose/

You can navigate around that site and identify your weed OR take several pics and send them to you local Ag ext agent and they will tell you what it is and how to get rid of it.

Copper Sulfate will kill it. I use this stuff on a couple of ponds. Just spread a little by hand with a rubber glove and it will kill it in a few weeks. Stuff is fairly expensive but at least you get to fish again.

If it is Primrose then Rodeo will kill it.
The active ingredient in most aquatic weed killers is 2,4D. Tractor supply sells it. If you buy it from them then get it from the farm & ranch section NOT up front with the regular yard items. It will have a higher concentrations of 2, 4D in it.


When treating tanks becareful and ONLY kill small areas at a time ! Kill one section and give it 8-10 days then kill another section. The decomposition of the dying plants takes out a LOT of oxygen !! If you treat the entire tank banks then you will likely have a massive fish kill. That tid bit of info does not pertain to ALL situations but please keep it in mind IF you have a major infestation and or are worried about your current fish.


I'd be glad to help out any way possible. Just let me know.
( not a professional & don't charge lol )

lucas_shane gave some good advice on precautions to take to prevent oxygen depletion from decomposing plants.

This info is also mentioned in the website I referenced above http://aquaplant.tamu.edu/management-options/water-primrose/


One danger with any chemical control method is the chance of an oxygen depletion after the treatment caused by the decomposition of the dead plant material. Oxygen depletions can kill fish in the pond. If the pond is heavily infested with weeds it may be possible (depending on the herbicide chosen) to treat the pond in sections and let each section decompose for about two weeks before treating another section. Aeration, particularly at night, for several days after treatment may help control the oxygen depletion.

Always read and follow all label directions.

The plant is definitely yellow water primrose. Genus Ludwigia

Check out the photos https://www.google.com/search?q=yellow+w...AQILw&dpr=1

A lot of the farmers/ranchers around here use grass carp. Seems to be very effective. Make sure you get sterile fish if you go this route!

Thanks for the help !

Check with county agent and get a granule called Blue Stone. Use it as directed. Only do about a fifth of the pond every other day. If you do the whole pond at once, all the fish will float to the top. I know this for a fact.

"Blue Stone" is Copper Sulfate. If it we were my pond, I would follow the recommendations of the professionals that are listed here:
http://aquaplant.tamu.edu/management-options/water-primrose/