Diffused air systems are not all they are hyped up to be.
This topic is probably the most controversial one I've seen on here, and everyone has a different opinion on it, largely in part due to the fact that it's all we have: opinions. There is no hard science to actually show what diffused air does for your BoW. There are too many variables: water temperature, air temperature, pond depth, biomass, access to wind, what type of water source you have, what species you have, access to electricity, etc, etc. MOST people on here say that aeration is better, not only to provide more DO, but to help with the overall breakdown of "bad stuff" in your pond. Some experts on here say that adding aeration allows your BoW to hold more fish, but as we've seen by this post, adding more fish or allowing your biomass to get really high can have deadly consequences, with or without aeration. It's a risk vs reward scenario, and I think that you are right when it comes to surface aeration, because there's virtually no risk in doing that, and you get a lot of the benefits of diffused air.
After reading a LOT of the aeration topics on this forum, it's been drilled into our brains to aerate, aerate, aerate, but, like you said, I don't think it's as hyped up as it should be. I'm in the process of receiving quotes for a 1/2 to 3/4 acre pond on my property and I think you've convinced me to just stick with surface aeration.
