Like Burger says, visibility measured by a white coffee cup. You'd be amazed at the difference between what you presume to be the visibility vs. measured using a white object on a string that is marked for measurement.
You're getting the hang of it, acre foot means one acre a foot deep in water. Don't give up, once the turbidity is cleared, it's a lot easier to keep it cleared.
You may think lime is expensive, and it is when bought in 50# bags. Call the local co-op or look in the phone book for fertilizer or farm fertilizer. They can deliver it in bulk VERY cheaply.
When I bought this place the pH of the soil was so outta whack that I had to apply 1 ton per acre for 2 years in a row just to get it back in the normal range.
