Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants duckweed question I need help

I have a 1\2 acre pond that is around 3 years old stocked with fish. Until this year my algea problems were slight but things have changed. I am not sure what has happened but I did lime the pond and add a small amount of liquid fertilizer early in the spring. I keep a powerhouse aerator fountain running around 16 hours a day and it is keeping the duckweed on one end but I sure would like to get rid of it for I fear it will deplete the oxegen level. I have treatred the water with aqua blue and recently added a 8-8-5 fertilizer "I think the numbers are correct or close to correct for the fertilizer". I can pump water from a creek to one end and let the duckweed flow out over the dam if I need to but I will have to install 250' of pipe and will this solve my problem or can I treat the water without harming fish and or the creek. Not sure what is the best but I want to protect the environment and my fish.

billewing,

Very possibly your problems are a direct result of fertilizing...explosive algae and weed growth following fertilization is something I have experienced and in hindsight should have expected, in spite of expert recommendations to add fertilizer.

Removing the fertilizer, by flushing out the pond, would seem to be a way to get things back to "normal".

One of the things I've learned about ponds is that things that work for some folks may not necesarily work for other folks in different situations. The pond maxim that says you should fertilize to increase fish populations may apply in some situations, but the side effects can be devasting. You may have experienced one of them.

billewing,

I too had a duckweed problem in my 1/2 acre pond. Nutrient levels were high from runoff and sediment. Went out of town for a few days and when I got back 40% of the pond was covered. My son and I built a "skimmer" out of 4" drain pipe and shade cloth. It took us about 4 hours to remove most of it. We put it in the compost pile. This seemed to be the safest with the least impact on the environment.

We still get some but not near as much as before. My guess is there are fewer nutrients in the water so the duckweed doesn't populate as fast. We now spot treat (with a 1 gallon sprayer) with Reward every 2- 3 weeks. Good luck.

Here in south Louisiana, duckweed is normal. Everyone has it because of all the wading birds.

From what I have learned, 1 domestic duck per acre is a good control. Of course wild ducks fly in, and we have no control over that.

Duckweed is not widely hated around here. It produces lots of oxygen, and I understand some of it gets into the water. It can shade out deeper weeds that are hard to control. In the right amounts duckweed takes up excessive nutrients and prevents excessive algae bloom.

I don't know if it's coincidental or not, but ever pond and lake I have seen with duckweed in moderate amounts has very pretty water and healthy fish populations. I'm not trying to sell you on duckweed. It does need controlling or it will dominate. When I finish my new pond, I am going to get 1.5 ducks, no doubt.

billewing :

I don't know about your pond goals but duckweed is not in mine. It covers the entire surface unless it is constantly removed or treated as stated/implied in the posts above. It shades out everything including the plankton which is the base of the food chain in our ponds. It is also very hard to fish in or through. While it may be worse under fertile conditions it will grow in infertile {not fertilized} conditions , like very clear tanic water swamps. I will not let it grow in our ponds , it comes out asap. ewest

Thanks to all for your replies. Am I hearing that it would be a good idea to get a couple of Ducks to help control the growth?

Looking at the pond this afternoon the algea has moved around and is streaking through most of the pond. I guess I will also try pumping water into the far end and try to wash it out. I am pretty new to pond ownership and am really glad I found this site.

Is there someway to post a picture so all could see my problem? My main concern is to take care of the fish. I have Bluegill, Redear, Bass, Catfish, 1 Grass Carp, and a couple of Koi. Have not fished them yet but they are a blast to feed and take care of. The pond is a wonderful thing to have at home. Sitting back here listening to the fountain break the water now. AHhhhhhh

billewing,

Grass carp are notorious for seeking out running water and going over spillways...I've lost a few that way...just a precaution you may want to take if you decide to flow water into and out of your pond.

I knew a guy who's pond overflowed after a big rain. I asked him if he lost any fish and he said. "Grass carp were pilin' out like clowns out of a phone booth". Thought that was kinda funny.

Duckweed and Watermeal Remedy : An aerator ( my choice is the Powerhouse too) and Tilapia.

Will Talapia live in Tennessee ponds year round? My pond is stocked with blue gill, redear, catfish, and bass. Would the talapia have an effect on the current population and can you catch them for a game fish?