Ducks with green spots on beaks?

[Nin315]

HI ALL. I have several ducklings I hatched out, who are now pretty much adults; maybe 90% grown. I noticed that they have green spots on their beaks..looks kind of like algae? Water wise, they haven't had an actual pool yet, but have had a mini pool about 4 inches deep, 2 feet sqare. They also have a regular waterer. The water in all is changed every day. Most of them don't seem much interested in the mini pool. They were let out of their cage to range around inside big run with plenty of grass and bugs about a month ago. I have 7 other true adult ducks totally separate,, way away, and those do have a baby pool which they love, they free range during day and put up at night in a tractor..None of my adult ducks have any sign of green stuff on them.. I've searched a lot thru this site and can't find any answers as to what is going on with the green...ALL of my ducks are healthy, active, and absolutely no signs of disease..they look great..any ideas?

 

[Miss Lydia]

HI ALL. I have several ducklings I hatched out, who are now pretty much adults; maybe 90% grown. I noticed that they have green spots on their beaks..looks kind of like algae? Water wise, they haven't had an actual pool yet, but have had a mini pool about 4 inches deep, 2 feet sqare. They also have a regular waterer. The water in all is changed every day. Most of them don't seem much interested in the mini pool. They were let out of their cage to range around inside big run with plenty of grass and bugs about a month ago. I have 7 other true adult ducks totally separate,, way away, and those do have a baby pool which they love, they free range during day and put up at night in a tractor..None of my adult ducks have any sign of green stuff on them.. I've searched a lot thru this site and can't find any answers as to what is going on with the green...ALL of my ducks are healthy, active, and absolutely no signs of disease..they look great..any ideas?

@Nin315 if you could post some pics that sure would help. and what breed/breeds are you talking about?

 

[Nin315]

https://www.backyardchickens.com/content/type/61/id/7498325/width/200/height/400

@Miss Lydia

Here is the best pic I can get. They definitely don't care to hold still for pics. It will only let me embed one image in messages..will have to put more in next message. One duck is a pekin and rest are pekin and Indian runner crosses. . as u can see, one has a lot more green on beak, but they all do have small amount. I hatched these this spring in incubator. My adults have no issues but are kept totally separate.
Thanks !

 

[Nin315]

 

[Nin315]

Resending first pic, doesn't show that image is there..

 

[Miss Lydia]

Resending first pic, doesn't show that image is there..

I am pretty sure it's normal but I'll see if i can find some info on it. for now here is a thread with some discussion.

https://www.backyardchickens.com/t/425746/green-spots-on-duck-bill