Well I decided to go the Barley straw route and tossed it in a week ago.

Loosely packed in ten large onion sacks, 1.2 acre pond, spread out around edges, 4-5 feet deep, a cord attached to yank it out in the fall.

Filamentous algae is already showing early strong growth at the bottom near the edges.
Water temp is close to 50 degrees and not expected to rise for a while, temps below freezing at night this week.

We'll see how it goes as the water warms. I'll report back in a couple months.