Do not allow livestock to wade in the pond or animal waste to enter the pond. Do not treat aquatic weeds with herbicides during the summer months without consulting a weed control specialist, fisheries biologist or Extension agent. During extremely hot weather, check your pond regularly at sunrise for signs of stressed fish. If fish are observed at the pond's surface gulping for air, stop feeding the fish and aerate the pond as soon as possible. Oxygen can be added to the pond by circulating the water with an irrigation pump or by running an outboard motor around in the pond.
Commercial aerators do an excellent job of aeration.
The paddlewheel type is especially effective, as it moves a large volume of water. Although fish kills caused by pesticides, herbicides, or other chemicals are not as common as those caused by oxygen depletion, some do occur. Be very careful when spraying herbicides or other pesticides, as many are highly toxic to fish. Low pH can be increased easily by applying agricultural limestone. The amount of lime required can be determined by sending samples of the mud from the pond bottom to the NCDA Soil Analysis Laboratory for analysis.