Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Duckweed Duckweed Duckweed

I had a 50 year old pond that was completly full of duck and was silted in. I had the the pond cleaned out and is about 15 feet deep now. This pond was dry for over a year and I figured the duckweed problem would solve itself since i cleaned out all the silt. But this year it finally filled up and the damn duckweed is back. Does water Ph have anything to do with duckweed. Will liming the pond help or will I have to buy the expensive spray and keep spraying it until its gone?

This appears to be some helpful info about Duckweed:

http://www.lakerestoration.com/t-duckweed-control.aspx

Try stocking some Tilapia when water temp reaches 65 degrees. Rule of thumb, 40 pounds per surface acre for an average problem.

This is a quote from the above link to pondrestoration.com.

"Duckweed prefers eutrophic, motionless fresh water"

These are questions, because I have no experience with duckweed (although my daughters pond that I cleaned out this fall had some, but not too bad, so am interested in solutions)

If it prefers motionless water, I would assume a pond that has lots of access to wind it would all blow to one side? If a person could have more wind (like removing some select trees) would that help the duckweed situation? Big fan? (LOL, too much energy required). Water pump to circulate water?

Pond aeration creates small waves on the surface. Would aeration help push the duckweed to the banks and keep it from spreading across the pond? If so, if a person used a larger bubble diffuser (move less water for circulation purposes but the energy creates surface waves instead) to create more wave action on the surface would that help keep the duckweed problem to a shore problem?

Like I said, these are questions for the experts, not answers.

+1, though you probably dont need near that much tilapia. Tilapia also doubles as great forage for your predators.

brian

Is there a downside to adding Tilapia? I have thought about adding some this summer as the filamentous algae had started to be a problem last summer. My pond is only going on its second year so the forage fish are still filling up the capacity of the pond and the LMB and CC are in growth stages rather than reproductive.

Will the addition of Tilapia slow the growth or reproduction of my previously stocked fish?

It all depends on which part of the country you are in, and when the Tilapia are stocked in the pond. (If the primary reason for stocking is FA control)

Up here in the north, if the FA gets a good jump on the Tilapia, even 40# per acre isn't enough to get back ahead of the FA.

If you don't want forage for your predators (i.e. your pond goal is to have large BG and you want the LMB to eat the YOY and small BG) then stock 90+% Male Tilapia like they grow for the food industry. They won't last as long in the pond as pure Blue Tilapia (water temp wise) but they'll still eat the FA, although not as much as constantly spawning pure Blues.

I haven't noticed that in any of the ponds that I've stocked with Tilapia.

Duckweed is an equal opportunity plant. We see it in waters with a wide range of pH, alkalinity, and nutrient level. Haven't seen where water movement does any good. For chemical control have had excellent results with Clipper. Have not used tilapia specifically for duckweed control so don't know the answer to that one. Good luck.