Let me clear up some misunderstanding.
1) The goal of a bottom diffusion aeration system is to bring O2 to the bottom of the pond, so the fish have the whole water column to utilize, AND bringing O2 to the bottom of the pond will allow aerobic bacteria to colonize the organic matter at the bottom, which in turn will greatly reduce the amount of annual muck accumulation.
2) Placing the diffusers on the bottom in the deepest part of the pond is exactly how a system is supposed to be installed.
3) A properly designed and installed bottom aeration system will show minimal water temp change from top to bottom, and will also show minimal O2 differences from top to bottom. That is the purpose of a bottom diffusion aeration system.
4) When installing a bottom diffusion aeration system in a pond that has a thermocline set up, with a very low DO reading at the bottom, it is critical to use the correct start-up procedure to prevent a fish kill. You WILL kill the fish in the pond if you just turn the system on and walk away. It's not the low O2 water that is killing the fish, it's the H2S gas that is killing the fish.[/quote]
OK sorry let me clear up clear up the muddied waters as they say. I dont disagree with anything you are saying, but I dont believe that just because a hole has water in it there should be an aeration system. From his description, pics, and video that is a healthy ecosystem that in my opinion the only real issue is the excessive feeding...but i get why because he wants big BG. Those water temps and DO numbers are the same as mine in my BOW and everything is just as healthy but I dont feed my fish. I understand we are very far from each other but the water temps are the same.
To equalize the water temps and DO in his lake in my opinion is not needed, why do they need to utilize the entire water column when the waters they are inhabiting provide everything they need? BG survive in waters down to 1ppm, same as my PS's and my trout have made it in that low as well although they are stressed. He doesnt have trout but i'd recommend that anyone with trout not mix that water up or they will lose them for sure.
I also think that his lake is different than many others in the hotter states - it is spring fed and isnt showing signs of stress other than the algae from excessive nutrient load. Im pretty sure he also said that he only started aerating recently.
What I would do is since the lake is recovering by lowering the feeding and keeping the aeration, I'd try removing the aeration for a couple of days to see how the algae responds, and then stop feeding and leave the aerators on to see what happens - a few days should tell the story although it might be overloaded with excessive fish food already. but before doing that check the DO levels first thing in the morning as a baseline and then manipulate the system and check again. I also mentioned cascading the little water input as Im pretty sure it will help.
The only other thing not addressed is aerating the muck at the bottom, in his ecosystem Im not sure it is really needed, it is much different than most man made ponds/lakes. I would focus on letting it be a natural system that can sustain itself, just catch and eat some bluegill from time to time to deal with the carrying capacity of the lake. He can also snorkel it to check the quality of the water and see what the bottom is like.
The other thing I would do tend to the shoreline to develop the riparian areas, this might relieve some of the nutrient overload and help with the algae, and would probably do so within a short year or two to start.
We have many natural lakes in our area that are basically the same as his and mine that support natural fish and have for decades with no aeration, spring fed and shallow, little beauties.
I have aerated in the winter to keep my ice open for my trout but Ill have inflow/outflow this winter so I wont be aerating.
Cheers.
