I'm just a beginner too, but in my opinion...There are very few ponds that "need" aeration, but all ponds can benefit from it. ClayNpray has given some questions that will certainly help the conversation along.

The biggest benefits to aerations IMO are...

1.) to increase the amount of dissolved O2 in the pond so that you can stock/maintain higher numbers of fish.

2.) increase the aerobic decomposition at the bottom of the pond to reduce the aging process of the pond (the silting in of the nasty anaerobic sludge).

3.) to reduce the chance of a temperature shock or turn over due to a heavy cold summer rain event. This is more important with excessive watershed ponds like mine.

4.) improves the surface quality especially in small ponds.

Some additional questions.

1.) will your new pond get much wind action? Ponds with less wind will have less air to water interface, hence less do2.

2.) is 80 acres of watershed adequate for a 3 acre pond in your area? It sounds excessive as far as the rule of thumb of 10 to 1. My pond has excessive watershed and this helped me make the decision to aerate because a heavy cold rain could turn my pond over in a heartbeat. My thoughts are that if I can keep the water as cool and consistent from top to bottom using aeration, then the effects of a cold rain would be minimal. Not to mention, my pond will have O2 dissolved throughout the water column.

3.) Possibly the biggest question...does your desire for the pond hobby back up the money that will need to be spent and the time that needs to be invested for aeration? Neither the money or the time are that big of a deal, but it can be a deal breaker when you consider aeration for a 3 acre pond can cost several thousand dollars.

Anyhow, some stuff to think about.

Fish on!,
Noel