why the string algae in my bog?

[Steve knight]

I have a lot of plants right now and a lot of oxegenators and no green water but my new little bog has a lot of it. it's not a big deal but I wonder why? nitrates between 5 and 10

 

[addy1]

Nice warm water lots of sun. Where I have a little water over the pea gravel in my bog, I found a little algae growing, nice warm puddle and lots of sun lol

 

[Steve knight]

lots of sun there (well when we have sun) it's only een in the low 70's most of the time so that must be it.