Sam :

Aeration is good and the smaller and more fertile the pond the better it works. It would probably be very good for your pond.

HOWEVER : Be sure what you are dealing with first.

That looks like duckweed (DW) or watermeal (WM) to me (not algae) and if so aeration (unless it is very strong) will not kill it in a 7 acre lake. What is the cost of a system that will make and keep the entire lake in a strong boil? Waves/strong agitation will help keep it under control. DW is a major headache. There are threads here on the subject. Here are a couple.

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=14;t=000231;p=1

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=17;t=000077#000001