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Has anyone ever completely eradicated duckweed from their tanks?


CCA Members
Just looking for tips on completely getting rid of duckweed. I've lived with it for years, but I want to make a serious attempt to get it out of my tanks in the near future.

Anyone have experience or success stories?


CCA Members
Just overfill the tank and all the duckweed will flow out the top.
I have done it. It doesn't always work. You gotta get the submerged stuff. :)

My technique for eliminating it -- keep any plants from growing within about 3-4" of the surface, trim constantly. Manually remove as much as possible. Then, daily, for a week or two, swoop the top with a net to get those last bits. If there are pockets where it's growing submerged, blast them with a pump or syphon hose to dislodge it. You really have to stay on top of catching any bits that float up or they'll become a lot more.

A few things that'll help, in my experience. Goldfish are worthless because they eat everything else. Rosy barbs work great for it, and also control hair algae. Win win. Adding CO2 helps a lot, for some reason, too. I suspect that when the plants growing beneath the duckweed have plenty of CO2, the duckweed loses its atmospheric advantage, and can't compete as well. Combined with thinning, it just goes away.