Fishwife, congrats on the new venture. I wanted to comment on your original post asking about aeration and if you need it.A 5 acre pond being spring fed can be as much in need of aeration as a 1/4 acre pond.We get calls every week from around the country that start out " Ive never had a fish kill and Ive had this pond for XX years," the latest one is 12 acres 30 year old lake with a lot of open water.My intention with this post is to keep you investigating the need for aeration so you do not have a negative experience. With the information you provided one cant say "yes or no" as to the need for aeration.Your 5 acre pond should have a muck depth check done to see just how much organic matter you have on the bottom, the higher the level the higher the demand for oxygen.The age of the pond comes into play, The fish types and overall population,additional water source average depths, etc etc also come into play to answer your question.You may want to have the pond electro shocked also by a pro to give you an accurate idea of your overall health. These companies can also suggest different options for aeration to suit your future goals. If your pond is stratified at present then it can be a sediment bowl or nutrient sink in the lower 1/2 to 2/3rds.This means your pond is only 1/2 the depth and may be anaerobic until fall. When it turns if it is done slow your fish will have no problem.I dont want you to get a false sense of security if you are using the barometer of "alive fish or dead fish" as to weather your pond is healthy or not.Many ponds and lakes are on the "oxygen edge" and the lake owner has no idea how close they come to a negative experience. I hope others will revisit this thread as a I think it was left incomplete.Again my intention is to get you to make informed choices after you define the goals for your pond.Enjoy your new digs and I hope you old residence sells quickly for you.