cwooten,

Very interesting post. Roughly how big are the gypsum "boulders?" I like the idea of continuous release over a long period of time. If you don't mind me asking, where did you locate these boulders, and how did you get such a good deal??

We've used quite a bit of gypsum on our ponds, but it's the powdered ag gypsum that comes in 40 lb bags. It gave our big pond (4-5 acres) nearly a foot more visibility after we applied about 2.5 tons.

Interestingly, the gypsum first turned the pond a milky white color as it was bonding to the clay particles. About a week later, it slowly but surely started clearing.

To answer your question, then, you shouldn't need to do anything else IF 1- the boulder gypsum works like the powdered gypsum we used, and 2- the clay particles settled out in a jar test like you indicated. 2-2.5 tons certainly sounds like plenty for a 1 acre pond.

I'm assuming our powdered gypsum will work faster than your boulder gypsum, since ours should dissolve quicker. Thus, it make take a lot longer for you to notice the clearing effects than it does for us. However, I'm guessing that your method will provide better long-term effects than ours. We had to spread the gypsum about 1/2 to 3/4 ton at a time with about 2 week breaks before we really noticed the difference. Your boulders should hopefully be doing the work for you.

"Only after sorrow's hand has bowed your head will life become truly real to you; then you will acquire the noble spirituality which intensifies the reality of life. I go to an all-powerful God. Beyond that I have no knowledge--no fear--only faith."