Hi Bonnie,
I don't know what he was going to use. Some kind of styrofoam
floats on a pvc frame. He didn't want the screen to show, because I
complained about it uglying up the view of the pond from the street.
I actually don't want the cover down, covering up the view of the
fish. I want him to build an attractive, tall awning that looks like
it belongs there. He's worried about the cost of that. Maybe if I can
get enough anacharis that the fish won't decimate it, it would help.

Hi Ann,
I can't answer your question - just wanted to say "Hi". One
point though, what is going to keep the screen floating. I
have screen in the veggie filter as a mechanical filter and
it always sinks.