Wow I love that spring, many on this forum would kill for that lol including myself.
I honestly dont think you need the aerators, even though you have a gentle slope from the spring to the pond you could build a cascading type of water fall that would aerate the incoming water...basically a set of tiny stairs that the water falls over and adds DO. Google cascading aerator.
If your aerators doubled the algae then there is your answer and the fish were doing alright before the aerators I suspect. Im pretty sure that if you put an aerator at the bottom you will probably kill off all the fish in your pond so I wouldnt do that.
And I think that the food is your main nutrient issue and that probably yes you need to remove some fish. My 6 acre lake actually smells fishy so I know I need to remove some.
Very nice spot.
