Hi Dadeville - I am no expert but have done a lot of research and spent a lot of effort getting a very old and neglected pond back in shape on land I bought 6 years ago. You will get all kinds of opinions on aeration and there are definitely some knowledgeable folks. I think you can probably go with surface aeration since your pond is not that deep. Based on what you have stated, it seems to me that you probably have an overpopulation problem with both the BG and catfish. If the former owner fed but you have not fed then you have a lot of hungry catfish that probably are working the bottom hard looking for food. You don't have an especially large water volume so it won't take much agitation to affect the entire pond at all depths. They may also have had some success spawning in the past so you may have more than you think. My dad had a small pond with absolutely no spawning habitat and his channel cats multiplied like crazy because he was feeding. Once the feeding stops the catfish and BG will eat the young so the population is probably stable now but overcrowded. If the cats are all essentially the same size (10"- 12") as you indicated then you have stunted catfish and that is a result of overcrowding. You should try and pull out some BG also. If they are all about the same size and fairly small like the catfish it will confirm the stunting and overcrowding.

Good luck - pondmeistering is fun and can be addictive.................