I'm hoping it will help. Seems like it has cleared a little since then, but it could just be wishful thinking. I haven't taken another Secchi reading yet. I was only at 3" when I put the alfalfa in, less than I had originally thought.
UPDATE: Alfalfa seems to be working and only 2 weeks in. I checked the pond over lunch and I am right at 6" of visibility now. We'll see where it's at in another 2 weeks.
Schmidt, I'm late to this discussion and new to the forum. Years ago I read the same article referenced earlier and decided to try gypsum purchased locally (Lowe's). Long story short: I knew each pond would be unique in its requirements so I charted a gypsum vs. visibility chart (attached). I would dose gypsum, wait a few days and measure visibility. The lower curve is the first dosage; the pond turned over and I started dosing again and as you can see the curves were the same but picked up quicker the second time around with the higher curve. Knowing the curve for your pond will allow you to know how much gypsum to achieve how much visibility. If gypsum doesn't work try Applied Polymer Systems/Atlanta, GA--they have some good solutions if you can accomodate the required systems, which I have had a hard time doing. FYI our pond is small (.35 acres/6 ft deep).
Thanks for the information Cypress. We are sticking to the alfalfa for at least this year; may look at gypsum again in the spring though. I was up to about 10" visibility before I got hit with a strong algae bloom this week. I still have about 6" of visiblity but the water is pretty green.