A word of caution- beware of burrowing mayfly larvae. My pond had an excellent visibility of 36-48" until this past spring where it dropped to 4". I was baffled and pissed- I did all of the tests and deciphered that I had a mechanical disturbance. It wasn't wave action and I didn't have undesirable fish. I shut my aerator off and gave it 3 weeks to "heal" but that wasn't the cause.
One day I noticed a giant casing from a large, burrowing species of mayfly that had recently emerged. I knew this possible from past readings, but could it be that mayfly larvae where causing turbidity?
Knowing that copper compounds are toxic to invertebrates, I decided to drop a large Cutrine bomb on my pond while quoting Pulp Fiction "I will strike down upon thee with great vengeance and furious anger......" The next day there 1000's upon 1000's of dead mayfly larvae. There is no mistaken the large burrowing species. About 3 days later my pond began to drastically clear. The sediments of the pond bottom resembled swiss cheese from all of the holes and tunnels created by the giant larvae. My pond got back to normal. It was pleasant to view and enjoy, my fish began to eat their feed again, and my wife and kids started to swim in the pond again.
