Tony and everyone, I agree, (sort of). Yes, it all matters according to scale, and yes, there are natural events that can happen in a pond that won't happen in an aquarium.
Breaching a dam - breaking the glass on an aquarium.
Rapid water temp change - see my aquarium temp fiasco below.
Pesticides/herbacides - yeah, not much can be done there.
Light can be controlled in a pond (to a degree) by using pond dye. Aeration, yes, that's a big one pocketbook wise. But, I'm 1/3 the way thru a 3 year plan to install bottom and surface agitation aeration systems in a 19 ac pond. Anything is possible.
Temp can be controlled (to an extent) with a well. Look at what Cecil is doing for his trout. I had a 55 gal aquarium, and came home to dead fish one weekend. The heater stuck "on" and cooked 'em all. The only survivor was a baby softshell turtle that was in the tank.
I think that aeration would have helped with the fish kill. If it was aerated, there would have been a huge "bank" of oxygenated water, and the influx, even tho it was large, wouldn't have had as much of an influence on the pond. That's my take from this armchair, and I could be 100% completely wrong. If it was aerated, no hydrogen sulfide to affect the fish either.
I still think the basic principles are the same between ponds and aquariums (bio load, filtration, etc., etc.) but the scale of the "tank" changes tremendously.
