What percentage shade fabric for a pond?

[Jerry]

I have a canopy with a net over the pond (Herons)  It does fine.
I am close to making a huge canopy, arches 12 feet high!  It may be very dramatic.

The turtles and water plants love sun.  I am guessing 30% factor would be okay.  I do need to know, not guess.

[Julles]

The marginals will do better in part shade than the lilies.  Other than that, I can't tell you specifics.  I just know that when I put wires over my pond, and coaxed vines up them, I stopped having trouble with green water.  It's probably about 40% shade, but it's "moving" shade, as the sun moves across the yard.

[Jerry]

I agree, I have seen green water clear up with less sun.

I will check and see what the lowest factor is.

[mascot]

I'd say cover about 85-90% of the pond with shade fabric.   

[Jerry]

No way  35% at the most.