Will 20 ducks change the nitrate/nitrite levels in a 3/4 acre pond enough to kill off my fish? I had someone tell me this so I thought I would ask the pro's on here..2-4 feet sloping to 10 or so..thanks, David.

Welcome to the forum Blue Moon, they will not be a problem if you teach them to poop outside the pond and not in the watershed. Otherwise.

I doubt that the duck poop will kill the fish, but it will contribute to an algae/weed explosion, which will consume O2 at night. I've seen 1 pair of Pekin Ducks keep a 1/4 ac pond muddy with their constant dabbling.........

Long term I wouldn't want 20 ducks on my pond.

I've got 4-5 mated pairs of wood ducks in my large pond (7 acres) - I have historically run ducks/geese off when they show up but I'm trying an experiment this year just to see the effect that they will have.

I doubt that those Woodies will make any noticeable difference in your pond.

I usually have a pair of Mallards that nest on the pond, but they usually leave for places unknown a week or so after the ducklings hatch.

Last year I worked hard to keep it a goose free zone, and am still working on it this year.

You should be more worry about the pathogenic and bacteria introduction into the pond than the nitrate-nitrite+nitrogen into your pond. However, if the population is exceeding 100, you may worry about infestation for that pond size.

I got a bit better head count yesterday evening...12-14 ducks it appears. 6-7 mated pairs. I'm still not going to do anything to run them off as long as they don't call in all the cousins.

Side note, it's amazing to me how quickly they acclimatize. These are 100% wild ducks as far as I know, and when they first landed maybe a month ago all I had to do was walk out the back door and they were GONE. Now they tolerate me fishing and walking around the pond pretty well...I'm actually now able to get close enough to see the birds pretty well with the naked eye.

So I'm taking it as a no that 20 ducks will not harm the pond...Is this correct?? Leo please give me your opinion as well on Pathogenic and bacteria...I do have a huge population of channel cats as well as other fish as well..Bluegill,redears,LM Bass, and the cats...Thanks again in advance...I appreciate everyones help...David.

Blue Moon, they will hurt your pond big time. Wood ducks come and go but tame ducks always stay around. They will make for muddy banks and could muddy the water.

Blue Moon, as kenc indicated, if you allow the wood ducks to dwell in the long run, in larger population, they will take down your pond pretty quickly. It starts about 50, when they stir up the banks, or deep dive to cool down during hot days, as well as to forage.

pH, up to 100, no an issue.

Bacteria, you'll see a climb steadily as the population hit 30. Once it hits 50, the level climbs alarmingly. As the population hits 75, bacteria level don't double or triple from 50, the bacteria level climbs at an astronomical level. Base on where and what they eat, bacteria level impact to your pond is different. We have city lakes, roughly between 5 to 10 acres, which get monitored constantly due to human contacts for recreations. The management teams monitor and control both permanent and migratory residence based on the impact criteria. For a 5 acres, they don't allow the population to exceed 150, although these lakes are constantly receiving influent water sources, and the same rate of effluent output. Yours is influent, without effluent, which you may want to cap at 20.

Pathogenic, same as bacteria.

This thread has got me confused. It seems we started talking about 20 ducks, then there were comments leading up to as many as 150. It sounds like the 20 Blue asked about were likely migratory but that is an assumpion on my part. So my confusion is will the 20 ducks hurt his pond or not; given that if they are wood ducks they likely won't stay much beyond the hatch.

I believe the 50 to 150 might be an issue, but how about 20 which are likely not to stay very long.

Bing, 20 is not a problem. As kenc indicated, 20 ducks, if allowed, will create a permanent resident, which will then reproduce to great number. The key is the capping limit, whether they be migratory or permanent dwellers.

20 normally dwells in one area, but as other migratory birds spot the existing permament/temporary dwellers, they will congregate en mass. How's the old saying go? "Birds of a feather, stick together."?

Sorry for the confusion..I purchased 20 baby ducklings from a hatchery...rouens,Black swedish,mallards,and cayugas..These are the only ones that will be on the pond...The pond is 30 feet from my taxidermy shop so even though I do get a few migraters from time to time, it's only as they are moving through..Too much going on for anything wild to take up residence..I'm not going to have anymore than the 20 and some of them will likely fall to predation or other reasons...I have a small creek that has some water in it to so they may venture over to it as well..Hope this clears it up...Thanks, David.

Ah..20 permanent residence, and a few migratory. That shouldn't be a problem with bacteria and pathogen. However, just make sure to check on them from time to time as they go about their activities in the pond, with the stirring of the silt along the banks during the hotter days ahead.