I concur.

Sounds like your turbidity is plankton bloom.

Only way I know to clear your water up is to reduce fertility. Don't add any fertilizer, of course. If you have horses or cows in your watershed, do what you can to reduce runoff from the area. If your fish are healthy, reduce or stop feeding for a while.

A teaspoon per quart of gypsum is a very high dosage. The brown sludge caused by garden gypsum is normal and harmless. It's probably caused by the binder used to pelletize it. I've used huge amounts in a small minnow pond and the fish are not affected. In a pond, the wave action would soon break up the sludge, or it wouldn't form in the first place.

Shrimp