Being from Texas I understand the hesitancy to pump any precious water out of you pond. But, think of it this way. If you add enough lime to your pond at full pool to kill off all the fish then you have a pond full of un-inhabitable water. It may take a long time or even more money to return the pH back to the proper range. By pumping it down you save money on lime and whatever it would cost to get the pH back in balance. Then your pond would eventually fill back up with clean, fresh rain water. But, like I said, I understand water is precious in some parts of the country. So, you may be willing to incur these extra costs and time to not pump it down.
