My mother lives in a neighborhood with one of those big ponds that everyone co owns. My question is if the pond should be dosed with chemicals (as needed) annually or if an air diffusor is enough. I don't know how much different pond chemistry is from aquarium chemistry but I would think that chemicals would be needed annually at least. My moms EPA expert says chemicals and an air diffusor but her neighbor's "expert" says air diffusors alone. Do any of you guys have these ponds? This one is roughly 1.5 or 2 acres. Anyone know anything about maintaining them?