My wife and I bought our place in June 2007 and the previous owner had put in a small pond somewhere in the neighborhood of 1/5th acre. Based on how things seem to have been taken care of around the rest of the property, I'm guessing the pond received no maintenance at all. It was completely covered with filamentous alae (sic?). I took a depth survey myself from 30+ locations around the pond and came up with an average depth of just over 4' with a max depth of 11'. It's only source of water is runoff and at the time the pond was between 3 and 4' low. I applied 1/2lb copper sulfate around the perimeter and the algae problem was much improved. August of 2007 I installed a bottom aerator and that was the end of the algae problem (in summer I get a just a bit of algae growth, but nothing that concerns me). The first year we caught BG of all sizes but nothing above 8-9". The biggest of them being HBG. LMB of all sizes from fingerling up to 3 lb. Several black crappie were caught in the 8" range, unfortunately not knowing any better and being a crappie fisherman to begin with, they were returned to the pond. I stocked 10 8-10" CC that year as well, not having caught a single cat that year at all.
Last year the fishing really seemed to suffer. BG numbers and size were smaller, same sizes of LMB and small crappie. This year BG numbers and size are still small. We did catch a CC that was 4 lbs, and one crappie in the 11" range (again released). Next spring I will start removing the crappie. My concern are the size and numbers of BG. With the pond's size I'm primarily interested in BG, and less concerned with LMB. A population of CC would be nice to have for the occassional fish fry with there numbers being replaced when they are removed. I do feed but nothing seems terribly interested and I worry about fouling the pond. In 2007 they devoured the feed as soon as it hit the water. I do put in 5 lbs of FHM in the spring and fall. I know the BG are there, I can see them around the bank and we do catch fair numbers but they all seem small, mostly in the 3-6" range. The LMB we catch appear well fed. I'm assuming when I put the aerator in more of the pond became usuable to the fish so perhaps I'm having trouble finding the larger BG now. It just seems the fishing was better before the aerator.
Sorry for the long post, any advice is certainly appreciated.

Chris