Here is a great article about aeration I cut the startup procedure out for you.
"When an aerator is first installed it is important that you don’t begin running it constantly right away. If the aerator rotates the water column too quickly, it can actually cause a fish kill by moving the toxic gases throughout the pond in one fell swoop. The best route to take is to run the aerator for only 30 minutes on its first day, then shutting it off for the remainder of that day. The second day you should run the aeration system for one full hour then turn it off. The third day double to 2 hours, then to 4 hours the next, 8 the next, until you are running your system all day. This process will take 7 days to accomplish. Not only should this process be followed the first time an aerator is installed, it should be followed every time the aerator is turned on after an extended shutdown."
http://pondaerators.wordpress.com/2008/10/
