1. Before using anesthesia in fish, check water quality parameters for tropical fish aquariums in the locality. 2. Monitor any changes in water quality that result from anesthetic administration, especially pH and alkalinity. Have adequate buffering agents available to counter these changes. 3. Use one or two preferred agents, and become familiar with the effects they produce. 4. Where possible, withhold food from fish for 24 hours prior to administration of the anesthetic agent. 5. Try to anesthetize a few fish in a group first as a test batch. Wait 12 to 24 hours for signs of delayed mortality before proceeding to anesthetize the rest of the fish. 6. Always provide adequate aeration in holding vessels. 7. Where practical, use water that the fish has come from in the anesthetic tank. 8. Always have a container of the same water for the fish to recover in.