"Steve J. Noll" wrote in message
...
My Dad has a small 500 gallon pond...
It's old cement, painted, with sloping sides.
900GPH Rio 3100 in-pond pump,
Tetra PF3 biofilter. No bottom drain.
25W Aqua Ultraviolet UV.
Bunch of mostly small goldfish.
Lots of plants. Semi sun/shade.

Problem is a "powdery" kind of green algae
sits on the sloping sides of the pond.
If anything disturbs it it turns into a cloud of
fine algae. It's not string algae and it's not
pea soup algae. I think it's too fine to net.

Although there's good water flow it's not
enough to sweep this stuff out. It doesn't
adhere to the walls at all, and seems alive (green).

If it is sitting on the walls and not fouling/clouding the water, it's
probably just pond sweater algae. Having it is a good thing because it gives
your fish something to feed on, and more importantly tells you your water is
healthy. My sweater alage is about 1/4 - 1/2 inch thick and looks great if
you ask me.

BV.