Jimmy,
I'll take a shot...
Answer, all the above. Add the lime on the bottom, in the water, and in the area that drains into the pond. It should not hurt your grass unless you put it all in one place on top of the grass. In fact, it should help your grass utilize nitrogen more effectively. You didn't mention if you had stocked fish yet, and at 1/6 full, I'm assuming you have not yet done that.
