duckweed on a pond - Ask Extension
Our pond is covered with duckweed, I am using a pool skimmer to lift it out. Is there something else we can do or use on it without harming the enviro...
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duckweed on a pond #191182
Asked June 14, 2014, 3:43 PM EDT
Our pond is covered with duckweed, I am using a pool skimmer to lift it out. Is there something else we can do or use on it without harming the environment?
Ogemaw County Michigan
Expert Response
Hello,Thank you for using eXtension for your pond question. Using a pool skimmer to manage duckweed sounds like a pretty creative solution to your problem. Using an aerator or pond fountain can help to clear the center of the pond as these plants are floating and easily moved about. This can make scooping them out an easier task as well once the duckweed is pushed to the edges. Some fish will feed on them. Stocking your pond with fish can also help if your pond is deep enough to sustain them. Koi and goldfish will feed on duckweed but not extensively, it is not recommended that you use grass carp as they are weak feeders on duckweed. Here are some websites that might help you: http://ohioline.osu.edu/a-fact/0014.html, http://www.extension.org/mediawiki/files/1/1d/Pond_Management_and_In-depth_Response_to_FAQs_from_Pon... Additionally, shading the heavier infested areas with black plastic can kill the weeds in that section. Tie floats onto the edges of a sheet of black plastic and place over an area of your pond for 10 to 14 days moving the plastic to new areas as needed.
So where can we find Koi and are the goldfish you are talking about just the ones you can buy anywhere?
Hi, you pose an interesting question because the correct
answer is it depends.
Purists will say only from an approved breeder, others who
aren't so fussy will suggest any pet store that sells fish. I know that koi for example are priced by
breeding, size and age, etc. Gold fish
can also command high prices if you want the fancy ones of any size. However, if you are willing to give it a try -
I personally have had success with the regular run of the mill Department Store
(Meijer) gold fish and koi. Calculate maximum
fish capacity based on your pond size. But
you can start with a minimum number of your choosing and add more if needed.
You may need to invest in a few additional items though to
get started: A pump fountain or filter
if you do not have an inlet and outlet stream for your pond - a kettle pond; as
your fish grow larger a heron decoy to ward off predators. Heron need a 50ft radius to feed so won't
land near another one. If you start with
the real little ones (fry size) get more than minimum as they take time to grow
and fall prey to many things in the pond. The size of your pond determines the
volume of fish stocked and don’t forget they will breed if conditions are good.
Also plan to supplement their food this way you can also train your fancy fish
to come to the surface for viewing. No feeding in the winter, they start to go
into a sort of stupor when the water gets below 40F.
Here are some websites that offers advice for hobby fish
grower. NOTE that I am not endorsing any product or business but there are not
a lot of extension materials for goldfish ponds so I look to industry and
organizations for good information.
This one is from England: http://www.koicarp.net/beginners_corner/beginners.html
About the fish: http://www.garden.org/subchannels/landscaping/containers?q=show&id=972
How to calculate how many fish to put in your pond: http://www.naturalsolutionsetc.com/garden-pond-calculations.htm
Managing Michigan ponds for sport fishing: http://archive.lib.msu.edu/DMC/Ag.%20Ext.%202007-Chelsie/PDF/e1554-1994-print3.pdf
(this is for sport fishing but the principle is the same for hobby fish)
http://www.michigandnr.com/publications/pdfs/huntingwildlifehabitat/landowners_guide/habitat_mgmt/wetland/Building_Managing_Ponds.htm
Pond management guide pdf: http://pubs.cas.psu.edu/FreePubs/pdfs/uh137.pdf
