I have a pair of mallards that come and go in all of my ponds including one I just refilled that only has some filamentous algae on the bottom. They seem to be eating it or they are picking off snails.

Could they be eating the algae?

Yes. I have even read a story where one pond owner introduced some ducks for the purpose of controlling algae on their pond.

I have seen hen mallards eat small freshly dead blugill of the surface before.

I've read claims that a few mallards can help control algae and duck weed. I have had years where there are only accasional visiting wild mallards to years where I've raised a half dozen mallards that lived in my 1/2 acre pond. I've never seen any noticable reduction in FA or duck weed as a result of having the mallards. I know they eat some of it but it can't be much.

bz. Algae control, over the last several years I have good luck with product called Greenex, I also thinks it help keep the duck weed in control. Check out this site

http://nutritekinc.com/NWS2/Nutritek%20I...0Repellent.html

They also have products for insect control,all natural Garlic Shield

Troll

I have some large geese that I will donate to fertilize that algae so the Mallards have more to do. :p

Domesticated mallards will eat more FA than wild ones. Wild mallards tend to eat more FA when other foods are in short supply. I keep 8 domesticated mallards on my pond just to control the FA. They do a very good job.

Troll, thanks for the tip. I've tried other bacterial treatments but I'm afraid I can't afford to apply them the way your supposed to. I can't say that I've seen much benefit but perhaps if I never used them I'd have more problems. I didn't find a price on the Greenex.